A young woman walks into a laboratory. Over the past two years, she has transformed almost every aspect of her life. She has quit smoking, run a marathon, and been promoted at work. The patterns inside her brain, neurologists discover, have fundamentally changed. Marketers at Procter & Gamble study videos of people making their beds. They are desperately trying to figure out how to sell a new product called Febreze, on track to be one of the biggest flops in company history. Suddenly, one of them detects a nearly imperceptible pattern—and with a slight shift in advertising, Febreze goes on to earn a billion dollars a year. An untested CEO takes over one of the largest companies in America. His first order of business is attacking a single pattern among his employees—how they approach worker safety—and soon the firm, Alcoa, becomes the top performer in the Dow Jones. What do all these people have in common? They achieved success by focusing on the patterns that shape every aspect of our lives. They succeeded by transforming habits.