Do you have tips for Recalling what it was like before you understood?

Good question. Unfortunately, it seems that for recall, it's a case of "you either do or you don't", and this is probably where I'm most unique. The best advice I can give is to use the "Remembrance of Things Past" trick: think about any memory related to that time in your life, and see if you can trigger an association that leads back to what you were thinking then.

I super endorse Motivating each step, especially when it comes to math. I find I have a lot of trouble with advanced math textbooks that do not do this well (and that's most of them).

Very true. A good example is the definition of a limit in calculus. If you try to just read the formal, standard definition, your brain will feel like mush, but if you learn what the definition is trying to accomplish, all the variables it introduces suddenly make sense.