I think I'm better than a lot of people, but that's not because I'm particularly intelligent, it's because so many others are unremarkable.
This. Objectively, I had a 2120 on the SAT.. then dropped out before graduating. I'm above average (although it seems nearly everyone in this thread is "above average"), but acutely aware of my shortcomings. Apathy and lack of motivation have done a lot to keep potential at bay.