Experience

David L: Well now Ian. I have a little question for you.

Ian: OK David. What do you want to know?

David L: Why is a man imprisoned like a boat full of water?

Ian: You’ll have to give me the answer to that one David.

David L: Because he requires bailing out.

^{Source: “A Thousand and One Riddles, With a Few Thrown In”, book published by George Routledge and Sons Limited.}