Have you ever wonder this.................

I have wondered that, but as well, how even Goku's hair can be like it is. =O I guess it's in saiyans' genes and I bet their hair is different compared to normal human raise. :/ Dunno.

Well I don't remember when it said this but I think it was Vegeta that said that Saiyan (idk if I spelled it right) hair always stays the same no matter what.

I KNOW WHY HIS HAIR STANDS UP LIKE THAT!!! Because he's crazy! Ever notice how all the crazy people have hair that sticks up? Vegeta, Goku, Raditz, King Vegeta...