I was kinda shocked back in business school to learn that the age of an entrepreneur is a significant factor in success - the older you are the more likely you are to succeed. The explanation was that you have more contacts, more experience, and more money. That being said, there's probably no better way to increase your chances of success than failing miserably, preferably several times. The canonical example is Ray Kroc, who took over a little company called "McDonalds" starting at age 53.