Most of what you believe, you didn’t choose. We inherit these patterns of thought, feeling, and action, from the world around us and the people therein. Your brain’s graceful solutions to impossible complexity, but not yours. As a brain scientist, I spent fifteen years—military, Cambridge, clinical practice—looking for the instruction manual for this device in our head. I didn’t find it. But you can see the patterns, once you know where to look. Then you can choose which ones to keep.