Nova: In the 2019 London Marathon, a runner named Siobhan O'Keeffe felt her ankle start hurting at mile four. She kept going. By mile eight, her fibula snapped. She kept going. She ran eighteen more miles on a broken leg and finished the race. That same day, another runner named Steven Quayle broke his foot at about the same point and also finished. Now—is that inspiring grit or utter madness?

Nova: That's exactly the question Annie Duke asks in her book "Quit: The Power of Knowing When to Walk Away." Duke is a former professional poker player turned decision strategist, and she argues that we have a massive cultural blind spot: we worship grit and demonize quitting. But the truth is, winners quit all the time. That's how they win.

Nova: It is, and Duke backs it up with decades of behavioral science, poker wisdom, and some unforgettable stories. She argues that most of us don't quit too early—we quit too late. And that costs us time, money, happiness, and sometimes our lives. Today, we're diving into why quitting is so hard, when to do it, and how to get better at it.

Nova: So here's the core problem Duke identifies. From childhood, we're marinated in pro-grit messaging. "Quitters never win and winners never quit." "If at first you don't succeed, try, try again." The Little Engine That Could: "I think I can, I think I can." Even the English language itself sides with grit—if you're gritty, you're steadfast, resolute, determined. If you quit, you're a loser who gave up.

Nova: Absolutely, and Duke is not anti-grit. She actually references Duckworth directly and says grit is essential. But she makes a crucial distinction: success isn't about sticking to everything you start. Success is about picking the right things to stick to and quitting the rest. Duckworth herself has written about the importance of trying lots of things to find the one worth sticking with, which requires quitting most of them.

Nova: Exactly. That's one of Duke's central refrains. Every time you choose to stick with something, you're simultaneously choosing to quit everything else you could be doing. And here's what Duke points out: by definition, anyone who succeeded at something stuck with it. That's always true in hindsight. But it does not mean that if you stick with something, you will succeed at it.

Nova: The most dramatic example in the book might be Stewart Butterfield, the founder of Slack. He had poured years and millions of investor dollars into a multiplayer online game called Glitch. It wasn't working. He made the painful decision to shut it down and lay off most of his team. But by quitting Glitch, he freed himself up to notice the internal messaging tool his team had built while developing the game. That tool became Slack, which sold to Salesforce for nearly twenty-eight billion dollars.

Nova: Right. And here's the kicker: Butterfield later said that if he hadn't quit Glitch, he wouldn't have been able to see Slack for what it was. The option to quit is what allows us to react to new information. Duke says decision-making in the real world requires action without complete information. Quitting is the tool that lets us update our course when we learn something new.

Nova: If quitting is so valuable, why is it so hard? Duke walks through a parade of cognitive biases that essentially handcuff us to bad decisions. The headliner is the sunk cost fallacy.

Nova: Yes, first identified by Nobel laureate Richard Thaler in 1980. The sunk cost fallacy means we factor in the money, time, and effort we've already spent when deciding whether to continue—even though those resources are gone no matter what. Duke describes it vividly: sunk costs snowball. The resources you've already spent make you less likely to quit, which makes you more likely to accumulate additional sunk costs, which makes it even harder to quit, and on and on.

Nova: That's exactly the image she uses. But sunk cost is just the beginning. There's also loss aversion from prospect theory—the Nobel-winning work of Kahneman and Tversky. Losses hurt about twice as much as equivalent gains feel good. So when we're losing, we become risk-seeking because we desperately want to avoid locking in that loss. We'd rather gamble on a turnaround than accept the pain now.

Nova: Then there's the endowment effect: we overvalue things simply because we own them, including our own ideas and beliefs. Status quo bias: we prefer what's familiar even when change is clearly better. Omission-commission bias: we're more forgiving of bad outcomes from sticking than bad outcomes from switching. And cognitive dissonance: when new information challenges our beliefs, we rationalize it away rather than update our thinking.

Nova: And here's the most uncomfortable one: identity. Duke writes, "When it comes to quitting, the most painful thing to quit is who you are." We tie our identity to our projects, careers, and beliefs. Quitting feels like admitting, "I'm not the person I thought I was." That's why we stay in prestigious but miserable jobs, or cling to public opinions long after the evidence changes.

Nova: Duke makes a brilliant ironic observation about that. She says our desire to be viewed as rational by others actually makes us less rational. We think changing our minds will make us look inconsistent or flaky, so we stick with things that are clearly failing just to project consistency. We're defending ourselves against imagined judgment.

Nova: So how do we overcome these biases? Duke offers practical tools, and the most powerful one is what she calls "kill criteria."

Nova: Kill criteria are pre-commitment contracts. Before you start something, you define in advance the specific conditions under which you'll walk away. The format is "states and dates": if by a certain date I have or haven't reached a particular state, I quit. The classic example is Mount Everest. Climbers set a turnaround time, typically 1 p. m., before they ever leave base camp. No matter how close you are to the summit, when the clock hits 1 p. m., you turn around.

Nova: Exactly. And crews that have ignored their turnaround times have literally died on the mountain. The research shows that pre-committing to kill criteria makes a huge difference. Barry Staw's work demonstrated that people who set exit conditions in advance behave like someone fresh to the decision, unburdened by sunk costs.

Nova: Duke says the best moment to set kill criteria is actually when you first start thinking, "Maybe I should quit." That's when you have real knowledge of what's making you unhappy. You sit down and write: what signals would tell me at the end of six weeks that this is no longer worth pursuing? It has to be both a specific state and a specific date, or you'll just keep moving the goalposts.

Nova: That's the spirit. Now, another tool is thinking in expected value, which Duke learned at the poker table. Instead of asking "Can I make this work?" you ask: what are the possible outcomes, what are their probabilities, and how do they compare to my other options?

Nova: Yes. A doctor named Sarah Olstyn Martinez contacted Duke. She was miserable as a hospital administrator but was afraid to take a new job at an insurance company because, in her words, "What if I take the new job and I don't like it?" Duke asked her: what's the probability you'll be happy in a year if you stay? She said zero percent. And what's the probability you'll be happy if you switch? She guessed fifty percent. Fifty versus zero—it wasn't even close.

Nova: Exactly. And the data backs this up. Economist Steven Levitt set up a website where people could flip a virtual coin to make big life decisions—quitting jobs, ending relationships, going back to school. Twenty thousand people used it over the course of a year. When Levitt followed up two and six months later, the people who quit were consistently happier than those who stuck. Duke's rule of thumb: if the choice between quitting and persevering feels like a close call, you should probably quit.

Nova: Because quitting on time will usually feel like quitting too early. The moment it feels emotionally safe to quit is well after the rational exit point. And the final tool Duke recommends is getting a quitting coach—someone who cares about your long-term interests more than your short-term feelings.

Nova: If the father of behavioral economics needs help with this, the rest of us definitely do. The quitting coach doesn't have to be a Nobel laureate. It just needs to be someone you've explicitly empowered to tell you hard truths. When you're emotionally and financially invested, it's nearly impossible to be objective. Someone on the outside can see what you can't.

Nova: One of my favorite concepts from the book is a mental model that comes from Astro Teller, the CEO of Google X, called "monkeys and pedestals."

Nova: Imagine you want to train a monkey to juggle flaming torches while standing on a pedestal in a public park. There are two components: training the monkey and building the pedestal. Building the pedestal is easy—humans have been doing that for millennia. Training a monkey to juggle flaming torches? That's the hard part, the potential dealbreaker. The monkey is the bottleneck.

Nova: Exactly. Because if you can't train the monkey, there's no point building the pedestal. But what do most of us do? We build the pedestal first. We design the perfect logo, refine the business cards, polish the minor features—all things we know we can do. It creates the illusion of progress.

Nova: Teller's approach at Google X is to find out if the project is feasible as fast as possible. His quote is: "If we find the Achilles' heel, thank God we found it after two million dollars instead of after twenty million." The sooner you figure out you should walk away, the sooner you can switch to something better.

Nova: And that brings us to Duke's most powerful reframe: the redefinition of waste. We naturally think of waste as backward-looking. We've already spent the time, the money, the effort—quitting would mean we wasted it. But Duke argues waste is actually a forward-looking problem. The time and money you've already spent are gone either way. The real waste is spending more time and money on something that's no longer worth it.

Nova: That's the tragic irony. And Duke says we need to redefine failure itself. Failure isn't quitting something that's no longer worth pursuing. Failure is continuing down a path that no longer has positive expected value. Failure is not following a good decision process.

Nova: And Duke has examples from everywhere. She cites the NBA draft study by Barry Staw and Ha Hoang. Teams give more playing time and longer careers to higher draft picks, even after controlling for actual on-court performance. They can't let go of the sunk cost of that draft pick. If professional sports teams with armies of analysts and millions of dollars on the line make this error, what hope do the rest of us have?

Nova: Right. And there's a haunting story in the book about a researcher named Jeffrey Rubin, who spent his entire career studying what he called "entrapment"—how people get stuck in losing endeavors. He was climbing his hundredth peak in New England when a heavy fog rolled in. His graduate student said they should turn back. Rubin continued. His body was found two days later. Even the expert couldn't overcome his own biases in the moment.

Nova: So let's pull this together. Annie Duke's "Quit" is fundamentally a book about making better decisions under uncertainty. The core insight is that grit and quit are not enemies—they're partners. Grit gets you up the mountain, but quit tells you when to come back down. The option to quit is what makes it safe to start things in the first place.

Nova: And perhaps most importantly, reframe what waste and failure mean. The waste isn't behind you, it's ahead of you if you keep going down the wrong path. Contrary to popular belief, winners quit a lot. That's how they win.

Nova: It is. And Duke is clear that this isn't about quitting things just because they're hard. There are hard things that are absolutely worth sticking to. But being picky about what you stick to frees up your time, energy, and resources for the things that genuinely move you toward your goals and your happiness.

Nova: Quitting on time will feel like quitting too early. But the data shows that the quitters end up happier. So here's to quitting better—and living better because of it.