You are different from the really great man in only one thing: The great man, at one time, also was a very little man, but he developed one important ability: he learned to see where he was small in his thinking, and actions. Under the pressure of some task which was dear to him he learned better and better to sense the threat that comes from his smallness and pettiness. The great man, then, knows when and in what he is a little man.

Listen, Little Man! (1948)