This past weekend I finished reading "Flowers for Algernon" — which was made into the 1968 movie "Charly" with Cliff Robertson. The basic premise of the book is that a retarded man undergoes an experiment and it provides him with superior intelligence — albeit only for a short period of time.
At one point near the height of his intelligence Charly writes: "Strange about learning; the farther I go the more I see that I never knew even existed. A short while ago I foolishly thought I could learn everything–all the knowledge in the world. Now I hope only to be able to know of its existence, and to understand one grain of it."
The passage is a wonderful reminder that at the heart of wisdom resides the acknowledgement of one's ignorance.