There is a famous fable by ancient Greek storyteller Aesop about a shepherd boy who habitually lied for fun. While looking after a flock of sheep near a village, every now and then he would cry "Wolf! Wolf!" to bring the villagers rushing, just to laugh at them and their naivety. One day the wolf did actually attack his flock, and the shepherd boy cried "Wolf!! Wolf!"- this time for real. Read more.