Thanks for a useful post. Personally, I've been using a similar technique when studying: sometimes you think you get it, and then suddenly, when it clicks, you realize that you actually haven't before. Recognizing this feeling turned out to be crucial for developing deeper understanding of the subject.
There was a weird moment once when I was reading to myself in my mind while copying a text and yet somehow misheard a letter (I think it was B instead of D). It felt as if I weren't aware of the original text in the first place and were simply writing down what someone else dictated.
Another thing is that I often remember words graphically, especially when trying to spell them correctly (e.g. in "successful" I imagine two blocks of "cc" and "ss" in my head as if I were looking at it on paper). In maths I can move symbols back and forth pretty easily in a formula and combine them with relatively simple constructions when necessary. Regarding sounds, I can reproduce short pieces in my head accurately enough to be able to transcribe them eventually, or at least to get the emotional feeling of a song, so to say.
Also one of my friends struggles with verbal thinking and thinks mostly implicitly, using concepts, if I understood that correctly, and they have a strong preference for non-verbal signs of affection (physical contact, actions, quality time etc.).