From the recent book about Steve Jobs, Becoming Steve Jobs:
Jim Collins, the bestselling author of the management classics Built to Last: Successful Habits of Visionary Companies and Good to Great: Why Some Companies Make the Leap … and Others Don’t, has a wonderful phrase to describe an essential characteristic of great leaders: deep restlessness. Collins applies the phrase to Steve, one of the two great leaders who inspire him the most... Collins believes this restlessness is far more important and powerful than simple ambition or raw intelligence. It is the foundation of resilience, and self- motivation. It is fueled by curiosity, the ache to build something meaningful, and a sense of purpose to make the most of one’s entire life.