Wow. This explains a huge amount, I’m slightly stunned. I had always assumed people were speaking metaphorically when they talked about seeing with the mind’s eye. I think I’m about a 4.8 on the scale shown here
https://en.wikipedia.org/wiki/Aphantasia. Can definitely relate to @spacedcowboy’s "orrery" model, though in my case it generally received as a source of annoyance, not a superpower sadly :) and to the sdam you describe @deafpolygon.