There is an old song sung in my native language that I really love hearing. Its gist is this...
You may be brilliant and brainy but you need not be rich and successful
You may be rich and successful but that does not require that you have brains.
There is a lot of truth there. The rating will hurt you for a week or so then its back to routine work. People who get appraised better and not necessarily any better than you. If you feel confident inside that is what matters. If you get appraised badly consistently, just leave.
I know a guy from my team who got ratings like no one else ever might have got in a company. I should say how much it helps when you do all the work and love your manager.