A Clever Cow

A farmer had a cow. The cow was very clever, but the farmer didn't know that.
One day, the clever cow thought of a trick. The cow stood up, and rang a doorbell. Then, the cow ran back to the garden immediately, and feigned ignorance about it.
After that, the farmer came out of the house. He found nobody except the cow. He had never dreamed that the cow could ring the doorbell, so he didn't notice it.


This story tells us that people shouldn't be tied to preconception.