My experience was the opposite. School in America tried to make me just memorize a bunch of stuff and it didn't work at all, but using resources like Khan Acade

My experience was the opposite. School in America tried to make me just memorize a bunch of stuff and it didn't work at all, but using resources like Khan Academy to build understanding and working through proofs of everything was all I needed. Lots of shallow exercises did nothing for me compared to a few deep exercises/proofs and reading.