Following an especially angry argument, Mr. and Mrs. Smith went to bed not speaking to each other. Needing to arise early the following morning, Mr. Smith left a note on his wife's bedside table that said "Wake me at six."

An exasperated Mr. Smith awoke at ten the following morning and rolled stiffly out of bed to see a note on his bedside table: "It's six, you bum! Get out of bed!"