User:Cainad/Thinking cap

A typical thinking cap.

The thinking cap is a mnemonic enhancement device used primarily by people who don't mind wearing a cap while trying to think about something. The yarmulke is the earliest form of the thinking cap, invented by Abraham when he was informed by God that were not wearing enough hats. Since that fateful day, Jews have been spending an awful lot of time thinking about all sorts of stuff, which was just as well, since they wouldn't be allowed to do anything physical like farming their own land for the next several centuries.