"There's a joke about the balloon boy who has a balloon mum and a balloon dad and he goes to a balloon school with balloon friends ad a balloon principal. And one day, the balloon boy decides to take a pin to his balloon school, which is, of course, a disaster. And he's called into the balloon principal's office, and the balloon principal tells him, 'You've let me down, you've let your school down, you've let your parents down, you've let your friends down. But most importantly you've let yourself down'."

Source: Gabrielle Williams (2010). “Beatle Meets Destiny”, p.216, Marshall Cavendish