How ignorant we are! How ignorant everyone is! We can cut across only a small area of the appallingly expanding fields of knowledge. No human being can know more than a tiny fraction of the whole. It must have been satisfactory in ancient times when one's own land seemed to be the universe; when research studies, pamphlets, books did not issue in endless flow; when laboratories and scientists were not so rapidly pushing back frontiers of knowledge that the process of unlearning the old left you gasping for breath.
Mary Barnett Gilson (1877–?), U.S. factory personnel manager, economist, and educator. What's Past is Prologue, ch. 25 (1940).
On the overwhelming amount of material she found to learn when, after years in industry, she studied for a doctorate in economics at Columbia University and prepared to teach for the first time—at the University of Chicago.