My experience in school seems similar except I didn't get nice math courses until very late on and I was miserably bad at the memorization-based Calculus work (and I still am, but I can do abstract math very well). By then I was pretty disillusioned by school in general.

His luck probably helped quite a lot. Nobody really knows what they are good at or what they will enjoy until they do it. Even if it's 'harder' or 'easier'. Having a good mentor is difficult as well; they have to know their stuff, want to teach and mesh well with you.