Is it necessary to be a child prodigy?
keefe: It's worth noting that the average person starting a successful company is not in his early 20s. http://www.startups.co.uk/6678842907756695817/the-average-en... That's one article discussing this, there are others. 
The reason you hear about all the rich millionaires is that they make good stories and they're rare - people just don't talk about the guy working hard through his thirties to make a few million. Also, look at the big entrepreneurs - they very often come from MIT, Stanford, etc. and get their initial funding either from rich family or connections made at those schools.