Young entrepreneurs (or at least young at the time of a startup's founding) tend to get the most press: Jobs, Gates, Page, Brin, Zuckerberg ... 

Yet a study conducted by the Census Bureau and two MIT professors found the most successful entrepreneurs tend to be middle-aged or older, even in the technology sector. In general terms, a 60-year-old entrepreneur is almost three times as likely to start an extremely successful company as a 30-year-old, and nearly twice as likely to launch one that eventually ranks in the top 0.1 (that's point-one) percent of all companies.