A hallmark of wisdom is knowing when it’s time to abandon some of your most treasured tools—and some of the most cherished parts of your identity.

This book is an invitation to let go of knowledge and opinions that are no longer serving you well, and to anchor your sense of self in flexibility rather than consistency.

We favor the comfort of conviction over the discomfort of doubt, and we let our beliefs get brittle long before our bones. We laugh at people who still use Windows 95, yet we still cling to opinions that we formed in 1995. We listen to views that make us feel good, instead of ideas that make us think hard.

Part of the problem is cognitive laziness. Some psychologists point out that we’re mental misers: we often prefer the ease of hanging on to old views over the difficulty of grappling with new ones. Yet there are also deeper forces behind our resistance to rethinking. Questioning ourselves makes the world more unpredictable. It requires us to admit

Yet in a turbulent world, there’s another set of cognitive skills that might matter more: the ability to rethink and unlearn.

Yankees fan, I’m going to see if I can convince you to root for the Red Sox. The third section is about how we can create communities of lifelong learners. In social life, a lab that specializes in difficult conversations will shed light on how we can communicate better about polarizing issues like abortion and climate change. In

A hallmark of wisdom is knowing when it’s time to abandon some of your most treasured tools—and some of the most cherished parts of your identity.

We listen to views that make us feel good, instead of ideas that make us think hard.

Yet there are also deeper forces behind our resistance to rethinking. Questioning ourselves makes the world more unpredictable. It requires us to admit that the facts may have changed, that what was once right may now be wrong. Reconsidering something we believe deeply can threaten our identities, making it feel as if we’re losing a part of