Humor <--> Pain?

My old roomie TJ once pointed out that all humor is derived in pain somehow. I didn't want to believe it then, nor do I want to believe it now. But having spent the last 7 years or so casually reflecting on a 5 minute comment he made, I have to admit that it's generally true.

Try to come up with something funny that doesn't involve pain on some level. Hard ain't it?

Humor can involve something like slapstick (obviously painful to some participant)
It can make fun of stereotypes (something funny at the expense of some social group / person / object)
Often times we end up laughing at someone b/c of something absurd they may have done.

It's not to say that humor is painful or bad. I think that as long as no one is coming out scarred in any real way, what's funny is funny. But the next time you laugh at something, take a second to consider if TJ was right. Kinda scary sometimes...