Fear can protect us from hurting ourselves. It keeps us from driving too fast on the freeway, walking too close to the ledge of a tall building, or gambling too much in a high stakes poker game. At its worst, though, it keeps us from acting boldly in situations where we need to take a risk. It keeps us from making investments that can lead to success. It causes us to hide our true selves out of fear of rejection by others. It causes us...