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  • Writer's pictureLars Christensen

Clear Thinking by Shane Parrish


I finished this book in February 2024. I recommend this book 8/10.


Why you should read this book:

You should read this book to ensure you have a good grasp of how to make decisions. Parrish used to work for an intelligence service and became a known podcaster with the Knowledge Project, talking about the mental models and thinking patterns of people like Charlie Munger and Warren Buffett.


Get your copy here.


🚀 The book in three sentences

  1. Detach, use different lenses, look as far as possible, and write it down—for your thinking process and to evaluate your decision later.

  2. Good decisions can have bad outcomes. Be Stoic.

  3. When you are 80, good decisions and efforts will look different to you. Your priorities will have changed.


🎨 Impressions

  • The book takes you in a good direction. It ensures you dismiss your ego when making decisions. It has tools and rules for decision-making. And, in the end, it talks about how all decisions are different when you are on your dead bed.


✍️ My favorite quotes

  • Epictetus said, " It is inevitable if you enter into relations with people on a regular basis...that you will grow to be like them...Place an extinguished piece of coal next to a live one, and either it will cause the other one to die out, or the live one will make the other reignite...Remember that if you consort with someone covered in dirt, you can hardly avoid getting a little grimy yourself."

  • Richard Feynman said, " The first principle is that you must not fool yourself—and you are the easiest person to fool."

  • Neal Peart said, " If you choose not to decide, you still have made a choice."

  • Frederic Maitland purportedly once wrote, "Simplicity is the end results of long, hard work, not the starting point."

  • P221. Marcus Aurelius said, "Think of yourself as dead. You have lived your life. Now take what's left and live it properly.


📝 My notes and thoughts

  • P9. We're naturally wired to organize the world into a hierarchy. We do this to help make sense of the world, maintain our beliefs, and generally feel better. But when someone infringes on our place in the world and our understanding of how it works, we react without thinking. When someone cuts you off on the highway and road rage kicks in, that's your unconscious mind saying, "Who are you to cut me off?" You're reacting to a threat to your inherent sense of hierarchy. On the road, we are all equals. We're all supposed to play by the same rules. Cutting someone off violates those rules and implies a higher status. Or consider when you get frustrated with your kids and end an argument with "Because I said so." (Or the office equivalent: "Because I'm the boss.") In these moments, you've stopped thinking and regressed to your biological tendencies of reaffirming the hierarchy.

  • P10. They have many names, but for the purpose of this book, let's call them the emotion default, the ego default, the social default, and the inertia default. Here is how each essentially functions:

  • The emotion default: we tend to respond to feelings rather than reasons and facts.

  • The ego default: we tend to react to anything that threatens our sense of self-worth or our position in a group hierarchy.

  • The social default: we tend to conform to the norms of our larger social groups.

  • The inertia default: we're habit-forming and comfort-seeking. We tend to resist change and to prefer ideas, processes, and environments that are familiar.

  • P21. Our desire to feel right overpowers our desire to be right. The ego default urges us to feel right at the expense of being right. Few things feel better than being right—so much so that we will unconsciously rearrange the world into arbitrary hierarchies to maintain our beliefs and feel better about ourselves.

  • P25. Doing something different means you might underperform, but it also means you might change the game entirely. If you do what everyone else does, you'll get the same results that everyone else gets. Best practices aren't always the best. By definition, they're average.

  • P41. Here are four strengths you'll need:

  • Self-accountability: holding yourself accountable for developing your abilities, managing your inabilities, and using reason to govern your actions.

  • Self-knowledge: knowing your own strengths and weaknesses—what you're capable of doing and what you're not.

  • Self-control: mastering your fears, desires, and emotions.

  • Self-confidence: trusting in your abilities and your value of others.

  • P47. Too often, the people we ask for feedback are kind but not nice. Kind people will tell you things a nice person will not. A kind person will tell you that you have spinach on your teeth. A nice person won't because it's uncomfortable. A kind person will tell us what holds us back, even when it's uncomfortable. A nice person avoids giving us critical feedback because they're worried about hurting our feelings. No wonder we end up thinking other people will be interested in our excuses.

  • P49. Complaining does nothing to change the present situation you find yourself in, though. Thinking about how it wasn't your fault doesn't make anything better. The consequences are still yours to deal with. Always focus on the next move, the one that gets you closer or further from where you want to go. If you play poker, you learn this intuitively. You're dealt a hand based mostly on luck. Feeling sorry for yourself, complaining about the hand you were dealt, or blaming others for how they played their hand only distracts you from what you can control. Your responsibility is to play the hand as best as you can. You can put energy into things you control or things you don't control. All the energy you put toward things you don't control comes out of the energy you can put toward the things you can.

  • P51. "Will this action make the future easier or harder?"

  • P57. Charlie Munger elaborated on the same idea my real estate investor friend had put forth. He said, "When you play games where other people have the aptitude, and you don't, you're going to lose. You have to figure out where you have an edge and stick to it."

  • P65. The most important voice to listen to is the one that reminds you of all that you've accomplished in the past. And while you might not have done this particular thing before, you can figure it out.

  • P67. I asked, "If you could pick one trait that would predict how someone would turn out, what would it be?" "That's easy," he said, "How willing they are to change their mind about what they think they know." The most valuable people, he continued, weren't the ones with the best initial ideas, but the ones with the ability to quickly change their minds. They were focused on outcome ever ego. By contrast, he said, the people most likely to fail were those obsessed with minute details that supported their point of view. "They're too focused on proving they're right instead of being right," he said.

  • P70. Sed-confidence is the strength to focus on what's right instead of who's right. It's the strength to face reality. It's the strength to admit mistakes and the strength to change your mind. Self-confidence is what it takes to be on the right side of the right. Outcome over ego.

  • P74. Epictetus said, " It is inevitable if you enter into relations with people on a regular basis...that you will grow to be like them...Place an extinguished piece of coal next to a live one, and either it will cause the other one to die out or the live one will make the other reignite...Remember that if you consort with someone covered in dirt, you can hardly avoid getting a little grimy yourself."

  • P89. My role models:

  • Benjamin Franklin

  • Jocko Willink

  • Ryan Holiday

  • Tony Robbins

  • Derek Sivers

  • Epictetus

  • P97. Richard Feynman said, " The first principle is that you must not fool yourself—and you are the easiest person to fool."

  • P100. There is a gap in our thinking that comes from believing that the way we see the world is the way the world really works. It's only when we change our perspective—when we look at the situation through the eyes of other people—that we realize what we're missing. We begin to appreciate our own blind spots and see what we've been missing.

  • P102. Alcoholics Anonymous has a helpful safeguard for its members. They call it HALT—an acronym that stands for Hungry, Angry, Lonely, and Tired. When you feel like having a drink, they say, ask yourself whether any of these conditions apply. If so, deal with the real problem‚ hunger, anger, loneliness, or fatigue—instead of reaching for a drink. You can use the principles behind HALT as a safeguard for decision-making in general. If you have an important decision to make, ask yourself: "Am I hungry? Am I angry or otherwise emotional? Am I lonely or otherwise stressed by my circumstances, such as being in an unfamiliar environment or pressed for time? Am I tired, sleep-deprived, or physically fatigued?" If the answer is yes to any of these questions, avoid making the decision if you can. Wait for a more opportune time. Otherwise, your defaults will take over.

  • P105. Similarly, suppose your goal is to drink less soda. Rather than deciding on a case-by-case basis whether you're going to drink soda—something that requires a lot of effort and that is prone to error—make a rule instead. For example, "I only drink soda at dinner on Friday," or maybe, "I don't drink soda at all." Having a rule means not having to decide at every meal. The execution path is short and less error-prone. In a quirk of psychology, people typically don't argue with your personal rules. They just accept them as features of who you are. People question decisions but respect rules. Kahneman told me his favorite rule was never to say yes to a request on the phone. He knows that he wants people to like him, so he wants to say yes at the moment, but after filling up his schedule with things that didn't make him happy, he decided to be more vigilant about what he agreed to do and why. When people ask him for things over the phone now, he says something along the lines of, "I'll have to get back to you after I think about it." Now only does this give him time to think without the immediate social pressure, but it also allows a lot of these requests to just drop away because people choose not to follow up. He rarely gets back to any of these people and says yes.

  • P106. I Imagined the film crew watching me make breakfast for the kids and then going to work. While the crew would be expecting to see meetings and people asking me for things, what they'd see is not calls or meetings until lunch, so I could spend time working on the most important opportunity. This is where my no-meetings-before-lunch rule came from. We're taught our whole lives to follow rules, and yet no one ever told us about how we can create powerful rules that help us get what we want. I find it hard to go to the gym three days a week, so my rule is I go every day. I do not feel like going to the gym every day. In fact, some days I hate it. I also know it's easier to follow my rule than to break it. When it comes to the gym, going every day is easier than going some days. Creating personal rules is a powerful technique for protecting yourself from your own weaknesses and limitations. Sometimes, those rules have surprising benefits.

  • P108. If there were a recipe for accumulated disaster, it would be giving the best of ourselves to the least important things. The path to breaking bad habits is making your desired behavior the default behavior. To get on track with the report, I told my colleagues that until the report was submitted, I'd buy them all lunch if they caught me with my email open before 11:00 am. My being competitive and not wanting to buy them lunch created enough friction to keep me from checking it first thing in the morning.

  • P119. Neal Peart said, " If you choose not to decide, you still have made a choice."

  • P127. The best decision-makers know that the way we define a problem shapes everyone's perspective about it and determines the solutions. The most critical step in any decision-making process is to get the problem right. This part of the process offers invaluable insight. Since you can't solve a problem you don't understand, defining the problem is a chance to take in lots of relevant information. Only by talking to the experts, seeking the opinions of others, hearing their different perspectives, and sorting out what's real from what's not can the decision-maker understand the real problem. When you really understand a problem, the solution seems obvious. Later, we'll talk about the tells that reveal when people are solving a problem they don't fully understand. These two principles follow the example of the best decision-makers:

  • The definition principle: Take responsibility for defining the problem. Don't let someone define it for you. Do the work to understand it. Don't use jargon to describe or explain it.

  • The root cause principle: Identify the root cause of the problem. Don't be content with simply treating its symptoms.

  • P132. Remember that writing out the problem makes the invisible visible. Write down what you think the problem is, and then look at it the next day. If you find yourself using jargon in your description, it's a sign that you don't fully understand the problem. And if you don't understand it, you shouldn't be making a decision about it.

  • P137. Luckily, there's a way to convert the hindsight of tomorrow into the foresight of today. It's a thought experiment that psychologists call pre-mortom. The concept isn't new, it originates in Stoic philosophy. Seneca used premeditatio malorum ("the premeditation of evils") to prepare for the inevitable ups and downs of life. The point isn't to worry about problems; it's to fortify and prepare for them. The hardest setbacks to deal with are the ones we're not prepared for and don't expect. That's why you need to anticipate them before they happen and act now to avoid them. Many people think they're bad problem solvers when, in fact, they're bad problem anticipators. Most of us don't want to think about more problems; we have enough already. We think that before bad things happen, we'll get a warning, we'll have time to prepare, we'll be ready. But the word doesn't work that way. Bad things happen to good people all the time. We get off without warning. We get into a car accident. Our boss comes into our office and lays into us. A pandemic spreads through the world. No warnings. No time to prepare.

  • P138. The bad outcome principle: Don't just imagine the ideal future outcome. Imagine the things that could go wrong and how you'll overcome them if they do.

  • P139. The second-level thinking principle: Ask yourself, "And then what?"

  • P145. Frederic Maitland purportedly once wrote, "Simplicity is the end results of long, hard work, not the starting point."

  • P146. The 3+ principle: Force yourself to explore at least three possible solutions to a problem. If you find yourself considering only two options, force yourself to find at least one more.

  • P146. Safeguard: Imagine that one of the options is off the table. Take each option you're considering, and one at a time, ask yourself, "What would I do if that were not possible?"

  • P154. If you're having trouble assessing opportunity costs, it sometimes helps to put a price on them. For example, putting a price on those extra two to three hours a day spent commuting will make them more visible and easier to assess.

  • P155. If you find yourself struggling to determine specific criteria, it's a sign either that you don't really understand the problem or that you don't understand the general features that criteria are supposed to have. Those features include the following:

  • Clarity: The criteria should be simple, clear, and free of any jargon. Ideally, you should be able to explain them to a twelve-year-old.

  • Goal promotion: The criteria must favor only those options that achieve the desired goal.

  • Decisiveness: The criteria must favor exactly one option; they can't result in a tie among several.

  • P159. A lot of managers secretly enjoy being the bottleneck. They like the way it feels when their team is dependent on them. Don't be fooled! This is the ego default at work, and it puts a ceiling on how far you will go. It tries to convince you that you're the best, that you're so smart, so skilled, so insightful that only you can make the decisions. In reality, you're just getting in the way of the team performing at its best.

  • P161. There is only one most important thing in every project: goal and company. If you have two or more most important things, you're not thinking clearly. This is an important aspect of leadership and problem-solving in general: you have to pick one criterion above all the others and communicate it in a way that your people can understand so they can make decisions on their own. This is true leadership. You need to be clear about what values people are to use when making decisions. If I tell you the most important thing is serving the customer, you know how to make decisions without me. If you make a bad judgment call, but it puts the customer first, I can't fault you. You did what I wanted.

  • P161. Criteria Battle: Using sticky yellow notes, write out one criterion—one thing that is important to you, and then do a tennis bracket tournament to find the most important thing.

  • P185. If you've ever bought a mattress, you'll know exactly what I mean. You spend hours—if not days—looking at mattresses, reading reviews, comparing prices, and considering whether you're a hot or cold sleeper. You finally decide on a mattress and have it delivered, only to find that it isn't what you dreamed of. So you exchange it for your fallback option anyway. You could have saved hours or days simply by ensuring the store had a flexible return policy, deciding on a mattress within an hour, and moving on. When the cost of a mistake is low, move fast.

  • P198. The margin of safety is often sufficient when it can absorb double the worst-case scenario. So the baseline for a margin of safety is one that could withstand twice the amount of problems that would cause a crisis, or maintain twice the amount of resources needed to rebuild after a crisis.

  • P200. Here's a bottom line: Predicting the future is harder than it seems. Things are great until they're not. If things are good, a margin of safety seems like a waste. When things go wrong, though, you can't live without it. You need a margin of safety most at the very moment you start to think you don't.

  • P215. Obviously, we all want good outcomes, but as we've seen, good decisions can have bad outcomes, and bad decisions can have good ones. Evaluating decisions—ours or others—based on the outcome (or how we feel about the outcome) fails to distinguish luck from skill and control. Because of that, engaging in results doesn't help us get better. The result of resulting is instead stagnation.

  • P221. Marcus Aurelius said, "Think of yourself as dead. You have lived your life. Now take what's left and live it properly.

  • P221. The first point is about making effective decisions. The second is about making good ones. You might think they are the same, but they are not. Good decision-making comes down to two things:

  • Knowing how to get what you want

  • Knowing what's worth wanting

  • P232. What were the most important things, according to the people Pillemer interviewed? They included the following:

  • Say things now to people you care about—whether it's expressing gratitude, asking forgiveness, or getting information.

  • Spend the maximum amount of time with your children.

  • Savor daily pleasures instead of waiting for "big-ticket items" to make you happy. Work in a job you love.

  • Choose your mate carefully; don't just rush in.

  • P233. The biggest regret people had? Worrying about things that never happened: "Worrying wastes your life," one respondent said. According to Pillemer, "The elders make the key distinction between events that happen to us, on the one hand, and our internal attitude toward happiness, on the other. Happy in spite of. Happiness is not a passive condition dependent on external events, nor is it the result of our personalities—just being born a happy person. Instead, happiness requires a conscious shift in outlook, in which one chooses—daily—optimism over pessimism, how over despair. The more we age, the more we come to see things the way Marcus Aurelius did: "When you are distressed by an external thing, it's not the ing itself that troubles you, but only your judgment of it. And you can wipe this out at a moment's notice.

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