In the earliest stages of our educations it gets drilled into us that certainty is good, and phrases like "I don't know" or "I'm not sure" are lesser ways of thinking. That's a shame, says former World Series poker champion and self-professed "uncertainty evangelist" Annie Duke: being uncertain is a much more accurate representation of the world than concrete certainty—there is just too much blind luck in the mix. Most often we're dealing with probability, not premonition, but the more accurate you make your worldview, the better your predictions will turn out. Embracing what you don't know can help you make surer bets on the future. Here, Duke gives an eye-opening lesson on how to recalibrate your beliefs, the difference between confidence and certainty, and how to use uncertainty to cultivate flexible thinking, smarter decision-making, and more productive collaboration. Annie Duke is the author of Thinking in Bets: Making Smarter Decisions When You Don't Have All the Facts.