I'm no topper. Far from it. Just sharing my experience. I thought I knew concepts as I had seen some videos and solved many many ques on Gmatclub. But when i tried slightly medium-hard ques , i realised I simply didn't know much in the way of concepts. This was after what you'd call a decent raw score.
Dropped the act. Started chapters from scratch.
Played video. Made notes. Typed. Attempted their solved examples.
Then started gmatclub .
Again made notesm
Again attempted the misses.
Kinda like how we did in school.
Just watching videos, was the most inefficient thing I was doing. Because I was understanding alright, but not going to remember anything
Still a work in progress. L