When I was a college student, I worked in a college dining hall, and on my way to work at 5:30 every morning I walked past the home of one of my favorite professors. Through a window I could see the light on his desk, morning after morning.
At night I stayed late at the library to take advantage of evening study hours, and returning home at 10:30 or 11 o’clock, I would again see his desk light on. He was always poring over his books.
One day he invited me home for lunch, and after the meal I said to him, “Would you mind if I asked you a question?”
“Of course not.”
“What keeps you studying? You never seem to stop.”
His answer, I learned later, was in the words of another — but they had become his own.
“Son, I would rather have my students drink from a running stream than a stagnant pool.”