What is a really funny short joke?

One really funny short joke is: "Light travels faster than sound. This is why some people appear bright until they speak." The joke is formatted like a one-liner, consisting of two sentences with a snappy punch line.

Another funny short joke is: "I told my doctor that I broke my arm in two places. He told me to stop going to those places."

Good, funny short jokes are usually one-liners that include puns, ironies or witty turns of phrase. A short joke can also take a question and answer format, with a simple set-up and punch line. Unlike longer, story-based jokes, short jokes are convenient for tellers to memorize and deliver.