What is Ego ?

The Prime Minister of the Tang Dynasty was a national
hero for his success as both a statesman and military leader.
But despite his fame, power, and wealth, he considered
himself a humble and devout Buddhist. Often he visited his
favorite Zen master to study under him, and they seemed to
get along very well. The fact that he was prime minister
apparently had no effect on their relationship, which
seemed to be simply one of a revered master and respectful
student.
One day, during his usual visit, the Prime Minister asked
the master, "Your Reverence, what is egotism according to
Buddhism?" The master's face turned red, and in a very
condescending and insulting tone of voice, he shot back,
"What kind of stupid question is that!?"
This unexpected response so shocked the Prime Minister
that he became sullen and angry. The Zen master then
smiled and said, "THIS, Your Excellency, is egotism."
Meaning:- The best way to learn something is not by having it
explained to you, but by EXPERIENCING it yourself. This
is a very interesting and commmon way how Zen Masters
try to explain things to the seeker.