Kevin Kelly at Wired.com recently interviewed Fred Brooks, the author of The Mythical Man-Month. During their conversation, Brooks answers a question from Kelly about being "frank" with himself:
"You can learn more from failure than success. In failure you're forced to find out what part did not work. But in success you can believe that everything you did was great, when in fact some parts may not have worked at all. Failure forces you to face reality."
I think a powerful reason why intelligent people don't succeed is the fear of failure, when failure can really teach us how to succeed.
I often see students fear failure because they are more focused on the "A," the symbol of learning, than the learning itself.