Bill Gates stopped being a kid right about age 11, his father tells Wall Street Journal. And then he turned into a royal pain, at least for a while. In the most famous bit of family lore, Bill Gates Sr. says he had to chuck a glass of cold water over the head of his 12-year-old son during an outbreak of "utter, total sarcastic, smart-ass kid rudeness" at the dinner table. Soon after, the family enrolled him in a private school where he had more freedom—and discovered computers.
Bill Sr.—who helped guide his son through tough decisions like taking Microsoft public—is now co-chairman of the $30 billion Bill and Melinda Gates Foundation. The 83-year-old says he enjoys working with his son but never forgets that Bill Jr. needs his space. "He has very fixed ideas of some things," Gates Sr. says. "The dynamic of the family is that you don't cross him on those things, because it's a waste of time."