The Lion And The Hare

A Lion came across a Hare, who was fast asleep. He prepared to seize her.

Just then, a deer bounded past. The lion left the Hare to follow him.

The Hare, scared by the noise, awoke and scudded away.
After a long chase, the lion lost the deer. Then he returned to find the hare, but it was long gone.

On finding that the Hare also had run off, he said, "It serves me right! I let go of food that I had in my hands, hoping to get something bigger, and ended up with nothing."

Moral 

Extraordinarily high goals are sometimes unrealistic; Be content to attain smaller but achievable targets.