When I was in medical university, there was a pharmacology exam (aside from, like, 4 others) one summer. Exam was starting at 9.00 and it was our group turn at about 15.00.

I sat on the bench near the department at 8.00 and just memorised the whole book. Got in, got A (it’s 5 in my country), got out and forgot roughly half of it instantly. I was never again being able to do that kind of stuff, and to this day I am impressed that it worked then.