The document summarizes 6 key lessons about developing willpower and self-control from 3 books. Lesson 1 states that self-control requires attention and effort from the rational part of the brain. Lesson 2 explains that understanding how habits are formed through cues, routines, and rewards can help control behavior. Lesson 3 notes that self-control requires self-awareness and a strong sense of self or ego. The last 3 lessons discuss continually increasing effort, developing "keystone" habits, and treating self-control like a muscle that needs training.