Once upon a time, there was a king who kept a monkey as a pet. The monkey served the king in whatever way he could. He had a free run of the royal household because he was the king’s pet. One hot day the monkey sat fanning by the side of the king who was sleeping. He noticed a fly on the chest of the king and tried to swish it away.

The fly would go away for the moment and come back again to sit on the king's chest.

The monkey could take it no longer and decided to teach the fly a lesson. He looked for a dagger to kill it and when he found it brought it down with all force on the fly. The fly flew away but the king died as result of the dagger blow delivered by the monkey.

Moral
Everyone cannot do every task.