Human: What is a fable and why are they so popular? Assistant: 
A fable is a story that tells a moral lesson. They were popular in ancient Greece, Rome, China, and other cultures. Fables often feature animals as characters, which can make them easier to remember than stories about humans. The most famous example of a fable is "The Tortoise and the Hare", which was written by Aesop in the 6th century BC.