> What always surprises me is how "sleep" is the ingredient I need here. Yes repetition helps. But space out the repetition with sleep and "woah! i get it!" is often uttered.

I really relate to this. In fact, a lot of times, when working on a difficult problem, I’ll intentionally go take a nap when I feel stuck, and more often than not, I’ll wake up feeling like the problem is much easier than I thought before my nap. I can’t explain why it works so well—it just does!