There once was a boy who watched his family's sheep each day. One day, he was bored and wanted to have some fun.
He shouted to the people in the town, "Wolf! Wolf! A wolf is trying to eat my sheep!"
Many people from the town ran to him. When they got there, there was no wolf. There was only the boy, and he was laughing at them because they ran there for nothing.
Another day, the boy was bored, and again he shouted, "Wolf! Wolf!" People from the town ran to him, but the boy just laughed at them again.
Then, one day, a wolf really did attack the boy's sheep. The boy shouted, "Wolf! Wolf! A wolf is attacking my sheep! Help! Help!" He was very afraid and he shouted again and again.
But the people in the town who heard him thought, "The boy is only trying to play a trick on us." And no one went to help him.
The wolf killed all of the boy's sheep.
This is a very old and well-known fable. It has an important lesson: If you often lie, people will not believe you, even when you tell the truth.