This classic riddle asks: What kind of button can’t be unbuttoned?
The answer is: a belly button.
The word “button” immediately makes most people think of clothing. Shirt buttons, coat buttons, and similar fasteners can all be buttoned and unbuttoned.
But a belly button is not a fastener at all. It is the everyday name for the navel, so there is nothing to undo or open.
The riddle works because one familiar word has two very different meanings. Your mind starts with clothing, while the answer comes from the human body.
It is a simple example of wordplay, and that simplicity is what makes it effective. Once the alternate meaning of “button” comes to mind, the solution is obvious.
