The three intelligent men and the fool
Once upon a time, there were four friends who grew up together in a village. Three of them were good at school and grew up to be scholars. The fourth was a ne'r-do-well, who nearly flunked out. Yet, as childhood friends, they were inseparable.
When the time came for the four friends to leave for the city to make their way in the world, they decided they would seek their fortunes together. The three intelligent ones felt they could not abandon their friend at this time of need.
They set out one day and soon after found themselves in a forest. In their path were some bones. The first scholar said, "Those are the bones of a tiger. Let me prove it to you by assembling them." And he assembled them into the very skeleton of a tiger.
The second scholar, not to be outdone, said "Let me prove to you that I can put back its skin and bones and flesh!". And he did.
At this the third scholar leapt up and said, "You two are as fools! Let me show you how clever I am! I can breathe life into this creature with my knowledge of spirits, potions, and magic!"
The fool, who had been silent, now spoke up. "Friends," he said, "You are all so very clever. But you are bringing a tiger back to life! Are you sure of what you are doing?"
His friends replied, "Fool you are and fool you shall always be. Now, get out of our wa\". "Very well," said the fool and he prudently climbed a tree.
The third scholar breathed life into the tiger, which being hungry, promptly ate the three scholars, leaving the fool, atop a tree, unharmed.
Moral: beware of PhDs.
Source: the Panchatantra