Amazing teacher! I love what he says about repetition. Rote learning is not cool, but it helps with learning and mastering math immensely.
But in a way, I feel like many times, I reach understanding of a topic, after some information has sit in my brain enough that "i get it". I often don't feel I've done something special compared to my state the day before. So maybe it's all rote learning.
However I would also argue that memorization is the precursor to understanding.
I think the main issue with rote learning in schools is when only memorization is taught and tested. For example: teaching and testing how to solve the same type of problem and grading the accuracy of solving without having any critical thinking/application problems is, in my opinion, a mistake.