How to deal with failure and feelings of incompetence and low intellect?

wooooooow hold on there tiger. B+, A- is an average I was never able to have in my life. I have always been c+, maybe sometimes b-. I dont question my intellectual capabilities because i know just how crap their methods of testing me are. i sit somewhere and memorise a LOT of stuff, and the more you do it, the higher your grade. I have realized that it doesnt make you smarter though, it just shows how motivated you are to do well by testing how far you will go to get a better grade.