There's a second lesson here- if you teach people to their individual ability rather than to the average ability of a class or grade level, you get some amazing results.

Every other kid in the class was playing 'at grade level'. This kid wasn't so he got a lot of extra instruction.

But what if every other kid got the same level of extra instruction?
They didn't, because they performed at grade level and thus were determined to be satisfactory. But I argue that if you give every other kid in the class the same focus as OP's friend, you'd find a lot of people going much farther than they would otherwise.

This is one of the horrible things of our education system- kids aren't pushed to meet their potential, they're pushed to meet grade level.