How do you know a boy is growing up?
I think it's when he's just had soccer practice and he's dripping in sweat on the way home in the car and you mention that he's going to have to take a shower when he gets home. And instead of belly-aching about not wanting to take a shower, how he doesn't really need a shower, he could just wash his face, he says, "I think I want to start taking showers everyday." Very matter of fact. Not wanting to spoil the goodness of the decision, you quietly say, "Showering is good, especially on days with soccer practice." Indeed, showers everyday are good.
You arrive home and he takes a shower without any fuss or needing any help.
I think that's when you know a boy's growing up.