Can you resist everything but temptation? In a hedonistic age full of distractions, willpower is hard to come by—or even to understand why we would need it. Yet, it's actually the single most important factor in success and a happy life, more important than money, appearance, background, or intelligence. This book reveals the secrets of self-control. In it, Roy Baumeister, one of the world's leading and influential psychologists, and journalist John Tierney show us that willpower is like a muscle that can be strengthened with practice and improved over time. Recent laboratory research shows that self-control has a physical basis and is therefore strongly influenced by simple things like eating and sleeping—so much so that a life-changing decision can have a completely different outcome depending on whether it's made before or after lunch. Based on years of psychological research and packed with practical advice, this book teaches you how to painlessly harness self-control and discover the true power of willpower. The results are nothing short of life-changing.