When i was awarded my blue, i, like every blue belt i have ever talked to, felt a bit embarrassed as i felt i didn't deserve it. This was after almost 3 years training mind.
There are some good white belts at my club who can (probably ) tap me. They're younger and fitter and will almost certainly overtake me. But that's cool. I know i'm doing the best i can, and like to think that's why the guy who promoted me did so. And he knows BJJ better than any of us. He puts his rep on the line with every promotion, so who am i to question him?
My rule of thumb - do everything you do for the pleasure inherent in doing the thing itself. If you are doing it for any outside rewards or praise or recognition you're driving down a dead end street.