I’m no genius, far from it to be honest. But I went through most parts of high school without studying because I somehow remembered stuff being talked about in class. I just recalled how the teacher said required thing and what they were connected with. It was enough to get average grades.

Uni was a bit different. I had huge problems with classes focused on just memorizing stuff. Lectures was not mandatory and most teachers were terrible at explaining stuff so I ended up missing most of those as it gave me zero benefit.

To pass the exams I had to really understand some basic procedures where applicable (math, economics, etc). And I mean really understand to what’s going on and why, not just memorizing equations. Once I grasped the basic concept it was often quite easy actually (I wasn’t aiming for As) because everything made sense out of sudden.

That’s why memorizing heavy classes were such a pain for me. There were usually no such “basics” where you can build upon. I had a classmate which was exact opposite of me. She could memorize a whole lecture book over night just by reading it once or twice. And I mean memorize like basically she could start to finish it word by word. Did she know what she was saying/writing? Often times not, but as long as the exam was written, she had straight As because she just wrote whatever the teacher wanted to be there. IDK if she had photographic memory or what, but it was completely mind boggling to me, exactly like your roommate is to you. Maybe they function the same?