@ flint:
I guess I was referring to lines that aren't particularly funny in and of themselves, or even that they have to be in context. For example, if I were at the local grocery, and someone said "Ruthie Puthie died" and someone else said "What for?" I would find that really funny.
If someone else said "Why did Ruthie Puthie cross the road" and someone else replied "To get to the chicken" I would not find that funny but I would know that the person saying it thought it was hilarious.
Hell, maybe I am drunk right now!
What wolf said.