You'd be surprised. Some people can be naturally insane at Mario Kart. For example, my girlfriend owns it, plays it regularly, and is pretty damn good at it. I however, played it a few times when I was 7 years old on a Nintendo 64. The first time I played this game with her, I completely kicked her ass, despite not having played it in a decade.
So in conclusion, if you take a transfusion of my blood, you will become a god at Mario Kart.