Bilateral Thinking Puzzles

Q: Two men went into a restaurant. They both ordered the same dish from the menu. After they tasted it, one of the men went outside the restaurant and shot himself. Why?

A: The man lived on a houseboat and had run out of fresh water.

Another

This is another thing that seemed funnier a third of the way into writing it, from the Surrealist. 19th August 2005.