It says on his homepage that he got his first guitar when he was 15. Can't find any birthdates on him anywhere though on the net. But then again Steve Vai has been playing since he was 13 years old and now he's about 48-50 years old and still going strong.
I've been playing for about 4 years myself too, like everything else it takes a lot of practice to be that fast. Not that I'm anywhere close to that though.
