Boy who cried wolf is a short book or story from Aesop's fables.
We learn from the story: don’t be like the boy who cried wolf, where you keep saying somethings happening to get attention and it isn’t, ad when it does happen, no one bothers to care. Same applies to Bible stories, but on a broader scale. You learn from the mistakes of the characters in the book as a moral lesson not to do it yourself