If your friend is feeling down, you could play him a really, really sad sack song, and say, “hey man, THIS ONE is for you.”
After you do that he will probably be sufficiently offended, or even angry, then you can say, “I GUESS you weren’t so sad AFTER ALL.” and maybe, “wow, your face is really red!” or “you look really stabby, calm down”
Then, run don’t walk, because he is probably indeed, really stabby.
If he doesn’t become offended, sit and enjoy the sad sack music until you reach the age of 22, or until you stop enjoying this music, whichever comes first.
“you look really stabby, calm down” :D