Why do people who misunderstand what you say for something absurd; then decide it is a good idea to discuss how crazy what they thought you had said was?

I think it is very funny when I am talking to someone, and they misunderstand what I say and once they know what I said decide to go on talking about how weird what I did not say was, and what they were preparing to say to the preposterous statement I didn’t make!

Has this happened to you? Why not just leave the old thought process behind and move on with what was really said straight away? Are we that desperate for something out of the ordinary to happen?