This has affected me a lot though, I know what is going on in songs, but can't ever remember the right words, but still some how end up sining stuff that means the same thing :/
So if I put a visual bend on something I can quickly understand it and remember it, but that bend has to be mind (even when helped by an image on a book). If it’s someone else’s, I’ll be very hard pressed to remember it (but I can easily remember where it was).
So at school, when I had to cram, I fill my head with images and things like that. And with the help of the exams (written) and memory of the classes, I worked out the answers.
For me, I have the bad "factual" memory and good "conceptual" memory but unlike you, I also have aphantasia: a completely "dark" mind with no visuals.
I've always used the metaphor that my brain has really good "compression". Once I learn something it gets compressed into my worldview. I don't know how or why I know it but I can apply it. If academic achievement is any benchmark, I can apply it with above average aptitude.