Re: i am a 21yr old and i look really young for my age
No, I don't think you have any type of disorder, you're probably just a late developer - I have a brother who is the same. He's always looked years younger than he actually is, and lets be honest it's a nice 'problem' to have. Much better than the other way round!
As for the question 'do girls like men that look younger for their age?' I think it depends on the girl. Personally I've always prefered older men, but I have a few freinds who think the other way. One thing's for certain, you'll be glad that you look years younger when you hit 40!