I have a few friends who freak out over tests and worry about them incessantly, yet perform fantastically. Even after taking the tests, they have no idea how well they have done. I don't understand it at all. There's this girl who started shaking when the teacher said that the class did not do well on the test, yet she still got the highest grade.
I can usually tell what grade I am going to get when I am doing the test, I was able to predict all of my AP exam marks after taking the tests.
Is it possible that your friend is used to your paranoia around exam time, and is also used to seeing you get high grades in spite of your worries?
The only thing that sustains one through life is the consciousness of the immense inferiority of everybody else, and this is a feeling that I have always cultivated.
-The Remarkable Rocket, Oscar Wilde