Reminds me of a friend from high school who was one of the smartest people I've ever known. In multivariable calculus we weren't required to do the HW if we didn't want to. He never did homework and never studied outside of paying attention in class and still got 100s on all the quizes/exams. He went to MIT and failed most of his classes his first semester there. He'd never had to study before so he didn't know how. Like Terence Tao though he's doing fine now.