Carlos Slim Helu vs. Jeff Bezos

Every Sunday, Slim's father would give him a 5-peso allowance and required him to record his purchases in a ledger. Before going into business, Slim taught algebra at UNAM, a university in Mexico City.

Growing up, Bezos worked summers on his grandfather's ranch repairing Caterpillar tractors. Bezos met Google founders Larry Page and Sergey Brin in 1998 and managed to become one of the company's first angel investors, putting in an estimated $250,000.