Sometimes it seems the only thing that hurts more than being laughed at is being the one who's laughing at someone. When you laugh too hard it feels like you're dying. What is the evolutionary reason for this reaction? If laughing too much didn't hurt then it's possible people would just keep on going laughing forever which would lead to the degeneration of the brain and eventual insanity. Thankfully when you laugh too much your lungs are overworked and you lose breath. The pain that is experienced when laughing too hard often forces the brain to stop finding whatever you're looking at funny even if it's a naked midget on fire riding a unicycle with a poodle on its head or whatever you think is the funniest thing imaginable. The brain has to stop finding things funny eventually just the same way it has to stop finding people attractive, which is the same reason your marriage fell apart. It's all meant to save your brain from eating itself alive.