When Warren was a little boy fingerprinting nuns and collecting bottle caps, he had no knowledge of what he would someday become. Yet as he rode his bike through Spring Valley, flinging papers day after day, and raced through the halls of The Westchester, pulse pounding, trying to make his deliveries on time, if you had asked him if he wanted to be the richest man on earth—with his whole heart, he would have said, Yes.That passion had led him to study a universe of thousands of stocks. It made him burrow into libraries and basements for records nobody else troubled to get. He sat up nights studying hundreds of thousands of numbers that would glaze anyone else’s eyes. He read every word of several newspapers each morning and sucked down the Wall Street Journal like his morning Pepsi, then Coke. He dropped in on companies, spending hours talking about barrels with the woman who ran an outpost of Greif Bros. Cooperage or auto insurance with Lorimer Davidson. He read magazines like the Progressive Grocer to learn how to stock a meat department. He stuffed the backseat of his car with Moody’s Manuals and ledgers on his honeymoon. He spent months reading old newspapers dating back a century to learn the cycles of business, the history of Wall Street, the history of capitalism, the history of the modern corporation. He followed the world of politics intensely and recognized how it affected business. He analyzed economic statistics until he had a deep understanding of what they signified. Since childhood, he had read every biography he could find of people he admired, looking for the lessons he could learn from their lives. He attached himself to everyone who could help him and coattailed anyone he could find who was smart. He ruled out paying attention to almost anything but business—art, literature, science, travel, architecture—so that he could focus on his passion. He defined a circle of competence to avoid making mistakes. To limit risk he never used any significant amount of debt. He never stopped thinking about business: what made a good business, what made a bad business, how they competed, what made customers loyal to one versus another. He had an unusual way of turning problems around in his head, which gave him insights nobody else had. He developed a network of people who—for the sake of his friendship as well as his sagacity—not only helped him but also stayed out of his way when he wanted them to. In hard times or easy, he never stopped thinking about ways to make money. And all of this energy and intensity became the motor that powered his innate intelligence, temperament, and skills.