From Bob Peoples, relayed by my friend Eric Artman:

I believe in the law of conservation of ignorance.  That is, the more you know, the more you realize that you don’t know.  The learned ignorance replaces unlearned ignorance, but the total amount of ignorance remains constant.

I think not knowing is ignorance, but knowing you don't know is knowledge, not ignorance, so it isn't really correct.  It's a great thought, though...

By the way, Eric is a terrific artist, check out his work...  the piece at right isn't really entitled "conservation of ignorance" - or at least I don't think it is - but maybe it should be:

This drawing is inspired by mathematics and chemistry. I was inspired to create this drawing after pondering what brilliance was coursing through Erwin Schrödinger's mind when he conceived of the wave equations.