"There were 3 strings and they wanted to go to a restaurant for supper. The first string went in and the waiter looked at him and said "Are you a string?" and the string said "yes" so the waiter said "I'm sorry. We don't serve strings." The second string came in and the waiter looked at him and said "Are you a string?" and the string said "yes" so the waiter said "I'm sorry. We don't serve strings." Then the third string tied himself in a knot and frayed the ends. He walked into the restaurant and the waiter looked him up and down and said "Are you a string?" and the string said "No I'm a frayed knot (afraid not)."