The Boy and the Gumballs

A boy put his hand into a pitcher full of gumballs. He grasped as many as he could possibly hold, but he could not pull out his hand. The neck of the pitcher would not give way to his fist. Unwilling to lose his gumballs, and yet unable to withdraw his hand, he burst into tears and bitterly sobbed in disappointment.

A man standing nearby said to him, "Be satisfied with half a handful and you will easily draw out your hand."

Moral: Do not attempt too much at once.
or
                       Too much greed will not bring success

 Aesop