I think it's a learning process. We don't laugh at the same things we used to as a kid, do we? We learn about the world, about us, and about us in that world...and we laugh at how all this works as a whole. We recognize a pattern and that makes us laugh. And some day, as we get older, we laugh at the mere hint of a pattern. At that point, it's not laughter anymore. It's crying from outside in. Funny stuff.