Yes hormones, you seem to not recognize them when girls and boys go through puberty. My sons in his own world most of the time.
I think that my niece felt that way about growing up, but all kids are different. She will grow out of it im sure.... my sister has to bribe her to bath and clean up after herself. Its funny, you'd think they would care about how they smelled. She actually has her bathing rutine a part of her chores to get her allowance, lol. My sons the oppostie i have to fight with him for the bathroom, and he cleans up after me ! lol.