Nobel laureate Richard Thaler and behavioral economist Alex Imas revisit 'The Winner’s Curse' to show how decades of research confirm that people consistently deviate from rational economic models—not out of ignorance, but due to deeply rooted psychological tendencies. They unpack core anomalies: the winner’s curse in auctions, fairness-driven rejections in the ultimatum game, and cooperation sustained by norms and communication. The endowment effect and loss aversion explain why we cling to defaults—from unused gym memberships to passive streaming habits—and how smart defaults (like automatic retirement enrollment) can nudge better outcomes. Procrastination stems from misperceiving time ('defective telescope') and present bias, while mental accounting leads us to treat money as non-fungible—yet programs like 'Save More Tomorrow' prove these biases can be harnessed for good. Finally, the focusing illusion causes us to misjudge future happiness, making waiting periods and real-world testing essential tools for wiser choices.