The Polymath

Achintya Krishnan
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  • EDUCATION
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Join me on The Polymath in learning about a diverse range of topics in easy to understand podcasts to uncover complicated topics.

  1. MAY 4

    Episode 34: Marginal Thinking: The Next One, Not the Average

    Don't think about the average. Think about the next one. Most people ask "Is this good overall?" Marginal thinkers ask "Is the next one worth it?" At a buffet, you've paid $20 for unlimited food. Should you get a third plate? Average thinking: "$6.67 per plate, good deal!" Marginal thinking: "Am I still hungry, or will I regret this?" The cost is sunk. The only question is: is the next plate worth it right now? We'll show you why marginal thinking matters: ignore sunk costs, ask "what changes if I do one more?", recognize diminishing returns (first slice amazing, fifth slice regret), compare marginal benefit to marginal cost. Apply to eating, work (is this next hour productive?), relationships (is this next year valuable?), learning (is this next chapter useful?), business (what does this next hire add?). Combine with opportunity cost (what else could the next one be?), second-order thinking (what does the next one lead to?), and probabilistic thinking (expected marginal return). Decisions are made at the margin, not the average. Think incrementally.

    16 min

  2. MAY 4

    Opportunity Cost: What You're Really Giving Up

    The real cost of anything isn't the price—it's what you could have done instead. Every yes is a thousand nos. Buy a $50,000 car? The cost is $50,000 invested at 7% = $380,000 in 30 years. Spend 3 hours scrolling? The cost is everything else you could have done. Take a safe job? The cost is the risk you didn't take. Opportunity costs are invisible—they don't show up on statements. So we ignore them. We optimize for visible costs (price, time) and miss invisible costs (alternatives, compounding). We'll show you how to make invisible costs visible, compare alternatives not just single options, think in "cost per use AND cost of not using," and consider compounding. Apply to time (your scarcest resource), money (compounds exponentially), relationships (finite depth), career (skills compound), and attention (presence matters). Combine with probabilistic thinking (expected value of alternatives), second-order thinking (what does sacrificing this lead to?), and inversion (what am I NOT giving up?). Every choice has a cost. Choose wisely.

    16 min

  3. MAR 31

    Probabilistic Thinking: Dealing with Uncertainty

    Most people think in absolutes: "This will work" or "This will fail." Probabilistic thinkers think in likelihoods: "This has a 70% chance of working." Nothing is certain—everything is probability. But our brains hate this. We round small probabilities to zero and high probabilities to certainty. We confuse predictions with outcomes. We want stories, not statistics. We'll show you how to think probabilistically: stop using absolute language, assign rough probabilities, update with new information, think in expected value, and calibrate yourself. Apply this to investing (60% chance of outperforming), career decisions (70% chance of happiness), relationships (50-50 odds), and business strategy (40-30-30 success distribution). Combine with second-order thinking (what's the probability of each consequence chain?), inversion (which high-probability failure modes matter most?), and first principles (what's the range of likely outcomes?). You can't control outcomes, only odds. Probabilistic thinking is humbling—and humility is an advantage.

    15 min

  4. MAR 31

    Inversion: Working Backwards to Find Answers

    Instead of asking "How do I succeed?" ask "How do I fail?" Then avoid those things. Inversion means approaching problems backwards—from the opposite end. Carl Jacobi said "Invert, always invert." Charlie Munger says "Tell me where I'm going to die, so I never go there." Why does this work? Because we're better at spotting problems than solutions. Failure modes are specific; success is vague. We'll show you how to practice inversion: define your goal, flip it (how would I guarantee failure?), list the failure modes, avoid them. Apply this to wealth (how do I stay poor?), health (how do I die young?), relationships (how do I ruin them?), business strategy (how would competitors destroy us?), and decisions (what would make this a disaster?). Combine with first principles, second-order thinking, and systems thinking. Inversion is defensive—it helps you not lose. Use forward thinking to win big, but use inversion to avoid catastrophic mistakes. Simple, powerful, actionable.

    14 min

  5. MAR 20

    Episode 30:Second-Order Thinking: What Happens After What Happens?

    Most people stop at first-order effects—the immediate, obvious result of a decision. Second-order thinking asks "And then what?" It's about seeing the consequences of consequences, the ripple effects, the ways systems adapt and respond. We'll show you the cobra effect (how a bounty to reduce cobras led to more cobras), why crash diets backfire, why social media's first-order effect (connection) created second-order polarization, and how to practice this skill. Always ask "And then what?" Consider how people will respond to incentives. Look for feedback loops. Think across time horizons. Assume adaptation. This separates amateur decision-makers from strategic thinkers, short-term wins from long-term success, people who get blindsided from people who see it coming. Connect to systems thinking (structure determines behavior), feedback loops (consequences that circle back), and incentives (people respond in ways you must predict). The future belongs to people who can see it coming.

    14 min

  6. MAR 18

    Episode 29: First Principles Thinking: Building from Bedrock

    Most people reason by analogy—copying what works, following convention, doing what everyone else does. First principles thinking is different: breaking problems down to fundamental truths and reasoning up from there. It's how Elon Musk made rockets 10x cheaper, how Galileo corrected 2,000 years of wrong physics, how innovation actually happens. We'll show you what first principles thinking is, how to do it (identify assumptions, break down to fundamentals, reason up), when to use it versus when copying is fine, and why it's hard but worth it. This isn't about reinventing everything—it's about questioning assumptions when they matter, going back to bedrock truth, and building better solutions from scratch. Connect this to energy conservation (a first principle of physics), compound interest (a first principle of finance), and incentives (a first principle of behavior). First principles thinking is the foundation for all other mental models. Because if you can't identify what's fundamentally true, everything else is built on sand.

    14 min

  7. MAR 12

    Episode 28: Why Do the Rich Get Richer? The Mathematics of Advantage

    Why do the rich get richer while the poor stay poor? It's not about morality or work ethic—it's mathematics. Compound interest, network effects, economies of scale, information asymmetry, risk tolerance, path dependence, and winner-take-all dynamics all amplify existing advantages. Start with $100,000 and earn 7% returns, you gain $7,000/year. Start with $1,000 at the same rate, you gain $70. The gap explodes over time—not because of greed, but because percentages applied to large numbers produce large results. We'll show you why it's expensive to be poor, why early wins lock in future wins, why networks compound, why the top 1% capture disproportionate rewards, and what this means if you're starting from behind. The same pattern explains why popular kids stay popular, why hit songs dominate, why big cities keep growing. Advantages compound everywhere. Understanding this doesn't mean giving up—it means understanding the game so you can play it smarter.

    13 min

  8. MAR 10

    Episode 27: Feedback Loops: Why Things Accelerate or Stabilize

    You've already seen feedback loops without knowing it. When we talked about inflation spiraling, housing bubbles bursting, interest rates cooling the economy—those were all feedback loops. Today we're making the pattern explicit. Reinforcing loops make things spiral: wealth compounds, confidence builds, social media posts go viral, habits strengthen. Balancing loops make things stabilize: thermostats, supply and demand, your body temperature. Most real systems have both, and which loop dominates determines whether things grow, collapse, or stay stuck. We'll show you how to identify which loop is running in your life, how to interrupt negative spirals, how to amplify positive ones, and why most attempts at change fail (balancing loops resist). This isn't just theory—this is the machinery of change in your career, relationships, health, and finances. Once you see feedback loops, you see them everywhere. And once you can design them, you become dangerous.

    15 min
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5
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About

Join me on The Polymath in learning about a diverse range of topics in easy to understand podcasts to uncover complicated topics.

Information

  • Creator
    Achintya Krishnan
  • Years Active
    2K
  • Episodes
    34
  • Rating
    Clean
  • Copyright
    © Achintya Krishnan
  • Show Website
    The Polymath