At the same time, I think some amount of repetition is important. You don't get a true understanding of something by just studying it, you need to apply it "on

At the same time, I think some amount of repetition is important. You don't get a true understanding of something by just studying it, you need to apply it "on a couple dozen data sets" to get a feel for it, at least in my opinion. "Understanding" can initially be a bit transient.