In August, Mavis Wanczyk, a 53-year-old from Chicopee, Mass., cashed in her $2 Powerball ticket for a cool $758.7 million, the second-largest lottery payout in U.S. history. Wouldn't it be nice to win? Wouldn't it be nice to be like Ms. Wanczyk, who told her employer she would not be coming to work, not now and not ever? What about a jackpot of more than $473 billion? That was the mid-2017 market capitalization of Amazon.com Inc., a company that went public with a valuation of only $438 million.