The New York Times-bestselling author of How Not to Be Wrong and Shape navigates the landscape of what we don't know, steering us to a calmer, wiser place from which uncertainty is a source of wonder and creativity Humans are wired to worry, and there's a lot to worry about. It's almost a cliché to say we're living in an age of high anxiety. We could all use some guidance as to what's really worth fretting about, what isn't, and how to know the difference. And it turns out that Jordan Ellenberg has been thinking about these questions at a high level for a long time, and he has a lot to say. Don't Be Too Sure is Ellenberg's delightful, wise, and immensely helpful guide to how to think about navigating an uncertain world with less useless anxiety and more freedom. There are two kinds of uncertainty, he explains: the kind that's about the randomness of the world, for which he draws on the science of probability, and the kind that's about not knowing what other people will do, which calls for game theory. Seeing how probability and game theory intersect is a true art. Ellenberg helps us face the consequences of the universal human tendency to over-weight small probabilities, and to feel the same amounts of pain and pleasure very differently. (This is largely why, he shows us, it seems so much harder to get into a "good school" these days but it actually isn't; it's just a lot more random. And why online dating is so predictably miserable. And why we're even worse at being humble about the past than we are about the future.) He unpacks the tyranny of the single metric, and the equally bad habit of lumping the wrong things together and splitting the wrong things apart. He shows us how John von Neumann can help us be less anxious, even when he's talking about the end of the world. Don't Be Too Sure won't dispatch all of your anxieties, and it would be terrifying if it did. But it will help you stay looser and nimbler, in a place of greater epistemic humility, where you can live the questions, and give the right answers time to emerge.