One of the guys I work with was pretty much bald as you can get by the time he was 21.. about a year ago I made him a wig from a piece of shaggy carpet and an old belt for a chin strap. much hilarity ensued..
My dad was bald by the time he was 21, and both my grandpa's were bald at an early age too. I'm 25 and still have all my hair, but it's quickly turning grey. I guess you either lose the hair or lose the color.