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.'
One of several stories found here.