The Best Business Advisors? Your Family

Tesla Motors, Elon Musk
Jill Greenberg
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A Brother’s Keeper

Elon Musk is the CEO of two businesses: Tesla Motors, an upstart electric-car company, and Space X, a private rocket company. When Musk was 13, he and his younger brother Kimbal hatched a scheme to open an arcade near their school, which was foiled only when a city official informed them they would need an adult’s permission. Kimbal still serves as Musk’s sounding board. “Sometimes I want things to be true, even though they're not, and Kimbal is good at pointing those out,” Musk says.