The greatest accomplishments in life--believe it or not--are made not by the smartest people in the world but by those who didn't know enough to quit.  They were the ones who kept plodding, who kept practicing, who kept investigating until they stumbled onto success.  That fact was driven home to me when I was studying in the university.  There were two men in my classes who were geniuses.  Their IQs were way up there.  At the end of a class, they slapped their books shut and didn't open them.  They were smart.