The Flaw

There was once a learned scientist.. 

After a lot of practice and efforts, he developed a formula and learned the art of reproducing himself. He did it so perfectly that it was impossible to tell the reproduction from the original.

One day while doing his research, he realized that the Angel of Death was searching for him. In order to remain immortal he reproduced a dozen copies of himself.
The reproduction was so meticulous that all of them looked exactly like him. Now when this Angel of Death came down, he was at a loss to know which of the thirteen before him was the original scientist, and confused, he left them all alone and returned back to heaven.

But, not for long, for being an expert in human nature, the Angel came up with a clever idea. He said to the scientist addressing all thirteen of them, "Sir, you must be a genius to have succeeded in making such perfect reproduction formula of yourself. However, I have discovered a flaw in your work, just one tiny little flaw."

The scientist immediately jumped out and shouted, Impossible! where is the flaw?" "Right here" said the Angel, as he picked up the scientist from among the reproductions and carried him off.

The whole purpose of the scientist and his formula of reproduction failed as he could not control his pride and lost his life.

So while one's Knowledge and Skills takes one to the top of the ladder and makes one successful, however the three letter word "EGO" can pull one down immediately.