When you heard the "A man has fallen into the river in lego city" and you get so tired so you just change the words to make it less boring
John: Have you heard about the man that felt into the river in lego city?
Oliver: Yes, I heard it 1984932 times.
John: But, I bet you haven't heard about this one; A river has fallen into the man in lego city.
Oliver: No, I haven't heard that!