...when you do have a deep understanding, you have solved the problem and it is time to do something else. This makes the total time you spend in life reveling in your mastery of something quite brief. One of the main skills of research scientists of any type is knowing how to work comfortably and productively in a state of confusion.

-Anon http://www.quora.com/What-is-it-like-to-have-an-understanding-of-very-advanced-mathematics#ans873950

(emphasis mine)