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."