let's see... I got my first axe at 16 played for a year, messed around really... started again at 20 and it lasted a year again...

I bought my strat at 29 and I'm 31 now, I find that I have more patience to learn the things I need to accomplish what I want as opposed to just learning "what's fun" when I was younger. So I think it's entirely possible for someone to start late and still become a great guitarist.. it just depends on how far you wanna take it... Azrael is a good example of this. According to his post, he started at 18 but wanted to do it so now he's recording things for bands and himself and if you've checked out his tricks.. the dude is bada$$!!!