YES! I have total Aphantasia, (sight, smell, hearing, etc) and I cannot now, and have never been able to conjure up any image of literally anything. For 66 years I never in my wildest dreams had any inkling that the majority of humans walking the planet could actually call up images and other sense's input from their memory! BUT... As you said, when I'm right on the edge of nodding off, sometimes (very infrequently) I see shadows in my closed eyes of geometrical patterns slowly moving and re-arranging themselves. I have absolutely no idea what or where that is coming from, but at this stage of the game, I'm happy to "see" anything at all, especially something like this that seems to actually help lull me all the way to sleep.