My friend overheard the following conversation this weekend between her son and my son. They were quite serious, sincere, and thoughtful:
Her boy: Can you teach me some karate moves?
My boy: Do you promise not to use them on someone else?
Long pause. My friend catches a glimpse of her son's face. Pensive, wheels are turning, semi-distressed look on his face. (He has a twin sister...)
Her boy: No.
My boy: Then no, I can't teach you. (The ways of the ninja must wait another day)
Her boy: Okay.
Conversation over, boys move on to Transformers and Star Wars.