"Couple of tea" . Dzen story...

Professor of one of the Universities of Tokyo decided to take several lessons of Dzen Buddhism from one famous Master. Having come to it home, he immediately began to tell about why he wants to take lessons and as much he already read literatures on this subject. The master invited him to pass to the house and offered tea. Professor continued to speak, listing books which he read about a zen. The master began to give some tea in the guest's cup when the cup was full to the brim and tea began to pour out from it, professor exclaimed:
— The master, what are you doing, a cup already full, and water overflows!
— Unfortunately, your consciousness is very similar to this cup — the Master answered. — It is filled with various information, and any new knowledge will overflow. You come next time — with an empty cup.