Words of a Teacher

It is one of the pleasures of teaching to discover what trivial things, unremembered by the speaker will effect unpredictable revolutions in the mind of a student. One recent instance comes to my mind, from the mouth of a particularly brilliant person, and hence doubly gratifying: Do you know what changed my whole attitude to study? No. Well, when I was a freshman, you assigned some readings in Samuel Butler, and when I came back to report, I began telling you what I had learned. But you broke in and said Yes, yes. What I want to know first is, was it fun?
— Jacques Barzun, Teacher in America

Compare:

Many a teacher, and we ourselves, would probably be surprised if it came to light what precisely — of all the things we say — has made the proverbial deep impression on our pupils or sons. Thus, for a while we were taught Church history by Paul Simon, the friend of Heinrich Brüning, doubtlessly an extraordinary man; soon afterward he became professor in Tübingen and even Rector of the University shortly before the seizure of power by the Nazi regime. Later, he used to exaggerate and mislead people somewhat by referring to me as a pupil of his. But what, of all his erudite wisdom, have I consciously retained? Nothing whatsoever, apart from a single, incidental comment: when his mother died, one or other of us expressed the class’s sympathy, in more or less formal terms, as was the custom; evidently he was not expecting it and, for once caught off-balance in a way that revealed his more human side, he said spontaneously, You only know what a mother is when you have lost her.
— Josef Pieper, No One Could Have Known