So, a theory my friend's come up with has really interested me. She thinks that, since Ash was turned to stone by Mewtwo in the first movie, he's stuck in the body of a 10 year old forever, which is why we never see him age. I'd like to see some sort of turmoil for Ash over this; he's maturing emotionally, but not physically, so no one ever takes him seriously. Maybe he's finally had enough, and tells everyone. Or something like that. Bonus EXP: People that Ash has met in his adventures, but all grown up. Extra Bonus EXP: Someone has suspected this about Ash for a while, but just hasn't said anything.
Not Growing Up...