We have become remarkably sophisticated at measuring physical fitness. We track our steps, heart rate, sleep, pace, strength, and recovery. We understand that healthy behaviors support fitness, but they don't tell us how fit we actually are. Eventually we want to know what the body can do. How far can you run? How much can you lift? How long can you sustain effort? If we want to improve, we establish a baseline and train from there. We approach our brains very differently. Mo

There is a strange problem with happiness. Most of us spend enormous amounts of time pursuing the things we believe will create it: the promotion, the house, the relationship, the vacation, the financial goal, the next accomplishment. Somewhere underneath all of those goals is a quiet assumption: when I get there, I'll be happier. And sometimes we are. You get the promotion, buy the house, reach the goal, or finally take the vacation you've been planning for years. For a litt