> In various subjects, particularly abstract mathematics, I had to grind heavily in order to keep up with the class. I attended every office hours and pattern matched heavily, studying into the wee hours. (I had tried your method and failed in previous semesters).

Grinding will always fail with abstract mathematics because it distracts you from divergent thinking and spontaneous insights. The problem is that university courses are on a fixed schedule so people that need more time than allotted for this kind of study are not accommodated, which pushes a lot of people away from mathematics who could otherwise contribute.