I was at a swim meet for my son a couple weeks ago. Various teams often print up t-shirts with motivational sayings on them -- usually about swimming, of course, but I saw one that I believe is equally applicable for us "wanna-be" photographers, too:
"Hard work beats talent when talent doesn't work hard"
I know it's sort of a syrupy bumper-sticker quote, but I think it helps put our efforts in perspective. Each of us might never be "great". Most of us will probably never go on assignment for National Geographic, or shoot the Olympics, or be exhibited in a national gallery. I believe there's something to great art that can't be taught, and some people just don't have it, but with enough work, most people can learn to be very good, and very good is going to be better than a lot of people out there who claim to be photographers.
So keep working on improving, but more than that -- keep working. It'll pay off.