[bokonist]

Do you really think that everyone has the natural talent to be able to do well at calculus?

but rather because he is "learning to play them for fun"

But what is fun? A person experiences fun when they have a feedback loop of effort, accomplishment, and reward. If you are good at math, you get this from doing math and you find math fun. If you are good at Halo, you get this from beating levels, and playing Halo is fun.