This has been bugging me for a while, and I've never met anyone in the same boat as me.
To be short: I don't have a visual memory. As in, I can't visualize things with any kind of detail. The best that I can manage with my mind's eye is a vague blotting of color and form, sorta like someone with glaucoma or cataracts (I would assume). I mean, I can't even visualize what my own mom looks like in my head enough to draw her, though I could describe her to you no problem. If anything, I visualize things spatially (which makes me rather good at sculpture), but perceiving all 3 dimensions at once makes for poor 2D art - think Picasso-esque anatomy by default.
I have great regular eyesight and can draw from life quite well, but drawing from my imagination is like pulling teeth. I've been at it for years, but my from-memory anatomy is still terrible, I have no concept of how color works, and I'll be damned if I could draw the same thing more than once - even from different angles. I feel like it's really held me back in my development as an illustrator.
Does anyone else have this problem? How have you learned to work with it? It's damned frustrating and I'm curious to know if I'm the only fool who insists on pursuing art regardless of this hurdle.