the thinking person’s toolkit: 50 concepts that rewire how you see the world
a no-fluff reference list for real-world clarity and cognitive leverage
We live in a world that overwhelms the unprepared. A world full of noise, spin, incentives you can’t see, and people pretending to think when they’re really just reacting on loop. They react, rationalize, and anchor themselves to whatever belief keeps them comfortable.
Most confusion isn’t a lack of intelligence—it’s a lack of good tools.
This is a non-exhaustive list of the tools I come back to again and again. Mental models. Core concepts. Pattern languages for life—all used as leverage. A way to move through complexity and chaos without becoming part of it.
I’m not claiming these ideas will make you immune to chaos. But they will help you notice the structure inside it—and that alone makes you harder to trick, easier to trust, and far more dangerous to the status quo.
Think of these not as definitions—but as lenses. Use them honestly. Combine them. Break them when needed. And above all, keep updating.
WHAT’S IN HERE:
I’ve grouped these 50 concepts into themed sections—decision-making, behavior, systems, strategy, risk—so you can move through them like a toolkit. Some are mental models. Others are patterns, principles, or traps to avoid. I use these daily across writing, business, relationships, and self-regulation. You don’t need to memorize them. Just recognize them in the wild. That’s when they start working.
Mental models are compressed ways of understanding the world—tiny frameworks that help you make sense of complex things. No single model explains everything, but having a diverse set makes your thinking more flexible and precise. Your brain is running models whether you realize it or not. Better to choose them intentionally.
1. First Principles Thinking
First principles thinking is about deconstructing a problem to its irreducible parts—what must be true, regardless of tradition or trends—and rebuilding from the ground up. It’s how Elon Musk rethought rockets, and how you should rethink anything that feels “obviously” true. Default assumptions are where insight goes to die.
2. Second-Order Thinking
Bad decisions usually come from only asking, “What happens if I do this?” Better decisions ask, “Then what?” Second-order thinking forces you to look downstream—at consequences of consequences. It’s how you avoid short-term wins that create long-term traps.
3. Inversion
Sometimes the best way to solve a problem is to flip it. Instead of asking how to succeed, ask how to fail—and avoid that. Want to be healthy? Don’t eat like shit, don’t sleep 4 hours, don’t skip movement. Inversion reveals blind spots by forcing you to stare directly at the ditch.
4. Circle of Competence
Knowing what you don’t know is one of the rarest forms of intelligence. Most people would rather pretend to be right than admit they’re outside their depth. The circle of competence reminds you to stay grounded in earned expertise—and to expand it slowly, not performatively.
5. Systems Thinking
The world isn’t made of isolated events—it’s made of interdependent loops. Systems thinking trains you to see the big picture: patterns, feedback cycles, and leverage points. Instead of asking, “Why did this one thing happen?” you start asking, “What system produced this over time?” It’s how you move from symptom-chasing to root-cause clarity. Useful for everything from supply chains to emotional spirals.
6. Marginal Thinking
Marginal thinking is the habit of evaluating the next unit of effort, not the total. It asks, “What does one more hour, one more dollar, one more rep actually get me?” It’s how economists think about cost and return—but it applies to your time, your energy, and your relationships too. One more rep at the gym might build strength; one more hour tweaking a slide deck might just burn you out. Smart people overdo it all the time—this model keeps you honest about what’s still worth doing.
7. Base Rate Neglect
Base rate neglect is when you ignore the general odds and get lost in a shiny detail. Like assuming your startup will be the exception to the 90% failure rate—because your idea feels special. The base rate is what usually happens. If you want to beat the average, you have to account for it first.
8. Regression to the Mean
Extreme outcomes tend to drift back to average over time. Don’t get cocky when you win, or fatalistic when you lose. Zoom out. Regression to the mean is the idea that extreme results usually even out over time. A student who aces a test might do worse on the next one. A team on a losing streak might bounce back. It doesn’t mean progress isn’t real—it just means luck, momentum, and randomness play a bigger role than we like to admit.
9. Bayes’ Theorem
This is how you learn in real time. Bayes’ Theorem is a tool for updating your beliefs based on new evidence. You start with a prior assumption—then adjust as new information comes in. It’s not just math; it’s a mindset: stay flexible, stay humble, stay in motion. Most people double down when challenged—Bayesian thinkers adjust their probabilities. That’s how you get closer to truth in a foggy world.
10. Correlation vs. Causation
Just because two things happen at the same time doesn’t mean one caused the other. Ice cream sales and shark attacks both spike in summer—that doesn’t mean dessert makes swimming in the ocean dangerous. Mistaking correlation for causation is how bad science gets published and bad policies get made. Always ask: what else could be going on here?
Decision-making isn’t just a logic game—it’s pattern recognition under pressure. These tools help you weigh risk, tradeoffs, time, and probability without getting wrecked by emotion or ego. You’ll still make mistakes. You’ll just make smarter ones—and learn to learn form them.
11. Probability
Probability is about thinking in odds, not absolutes. Instead of asking, “Will this happen or not?” you ask, “How likely is this, given what I know?” Life rarely deals in guarantees—but most people think in black and white. If you want to stop being surprised by predictable outcomes, get comfortable thinking in shades of likelihood.
12. Expected Value
Expected value is how you judge if a bet is actually worth it. It combines risk and reward—you weigh the size of the upside and downside, multiplied by how likely each one is. A low-probability win can still be smart if the payoff is huge. High-probability traps can still destroy you if the downside is catastrophic. Use this lens to make decisions like a strategist, not a gambler.
13. Opportunity Cost
Every time you say yes to something, you’re saying no to something else—even if you don’t realize it. That’s the opportunity cost: the hidden price of your choices. Time, energy, attention, money—whatever you spend, you’re giving up something else you could’ve done instead. Smart decision-makers don’t just ask “Is this good?” They ask, “Is this better than what I’m giving up for it?”
14. Asymmetric Risk
Some decisions have low downside and massive upside. Those are the bets worth taking—over and over again. Starting a project, reaching out to someone, trying a new tool. If it fails, who cares. If it hits, it might change your life. The mistake isn’t failing—it’s never stacking the odds in your favor.
15. Sunk Cost Fallacy
Just because you’ve already spent time, money, or energy on something doesn’t mean you should keep going. That investment is gone. But people cling to it—jobs, relationships, business ideas—because they don’t want to feel like they wasted it. The truth? You waste it more by staying stuck. Know when to cut your losses and move along.
16. Diminishing Returns
More input doesn’t always mean more results. The first rep, the first hour, the first idea might yield a ton. But eventually, each extra unit gives you less. Diminishing returns remind you to stop chasing effort and start watching for the drop-off. The first 30 minutes of studying might be high-impact; the fifth hour is probably just you rereading the same sentence. This model helps you recognize when effort is no longer producing results. Instead of obsessing over working harder, it teaches you when to pause and break.
17. Compound Interest
Compound interest is the idea that gains build on gains—over time, small efforts explode into big outcomes. This isn’t just about money. Habits compound. Skills compound. So does neglect. The secret is consistency. Do the small thing often enough, and it becomes massive.
18. Compounding Habits
Habits are the human version of compound interest. They don’t work like switches—they work like snowballs. One workout doesn’t matter. Ten don’t matter. But a year of workouts? Life-changing. One day of eating healthy or journaling doesn’t do much. But when you repeat it regularly, the results start to multiply. Your habits build you, whether you notice or not.
That’s why I created THE DAILY 5—a process designed to help track small patterns over time so you can actually see what’s compounding and what’s not. The magic isn’t in what you do once—it’s in what you keep doing, even when no one’s watching.
The 5-minute daily ritual that changed how I think
·THE DAILY 5 is a weekly journaling practice for people who want to understand themselves better—but don’t have hours to reflect every day. It’s structured, intentional, and grounded in real self-awar…
19. Black Swan Events
A Black Swan is something you didn’t see coming, couldn’t have predicted, and can’t ignore once it arrives. Most people assume tomorrow will look like today. But every now and then, something rare and massive crashes into the system—COVID, 9/11, market crashes, viral fame. The lesson isn’t to predict Black Swans—it’s to build in a way that doesn’t break when they arrive.
20. Fat Tails
Fat tails are the part of the probability curve where the “impossible” lives. Most of the time, things are average. But occasionally, a single event is so extreme it overshadows everything else. In most models, extreme events are treated as “rare” and insignificant. But in real life, those rare events are often what shape everything. That’s a fat tail: when the weird stuff—outliers, booms, crashes—carry outsized weight. One blockbuster hit can fund a studio for a decade. One decision can ruin a career. It’s a reminder that unlikely doesn’t mean unimportant.
21. Scalability
Scalability means you can grow something without increasing effort linearly. Teaching a class in person? Not scalable. Recording a course and selling it forever? Scalable. Code, content, and capital all scale. Your time doesn’t. Learn the difference and build accordingly.
22. Leverage
Leverage is how you get outsized results with limited input. It’s force multipliers: capital, code, content, people. A leveraged person works once and gets paid forever. An unleveraged person works forever and barely gets paid. The more leverage you build, the less permission you need.
Life isn’t linear. It’s loops, delays, feedback, and emergence. These concepts help you see the hidden structure behind chaos—so you stop reacting to symptoms and start understanding the machinery underneath.
