Aphantasia and Me
Here's a fun one. I recently discovered (on account of it being recently discovered) that I have a condition called aphantasia, which boils down to the lack of a mind's eye. The best way to explain it is this (adapted from other sources):
Picture a beach. The waves are rolling in peacefully, the sky is a serene sort of blue. There's a tree nearby, leaves swaying in the gentle breeze. An insect crawls down the trunk, pausing for a moment before disappearing into the grass below.
Look a little closer: what shape are the leaves?
Now, given the lack of concrete information, you could be seeing just about any kind of tree on any kind of beach — all answers are equally valid.
But for me and those with aphantasia, we don't see the leaves at all. We don't see the insect, the tree or the beach. We don't see any of that, because our brains aren't wired to create mental images.
I liken it to CSS: I have a series of instructions that I know create an image, but until I produce it, I can't actually see it. I understand visual information on a conceptual level, not an actual one. It's hard to explain, because people who do see things in their minds can't imagine not seeing it, and people who don't...well, we have no point of reference.
A lot of people have been shocked when I told them about this relatively new discovery, because I think there's an assumption that as a creative writer, I must be "seeing" the imaginary worlds I create. But when I go back and look at the things I've actually written, what strikes me is that I very rarely actually describe the physical characteristics of things unless I'm trying to draw out a scene, or call attention to a detail. I almost never describe my characters except in functional terms, and I never take a detour to describe details around a room unless they'll affect the plot somehow.
(as a side note: in high school we read The English Patient one year, and I remember the teacher gushing over the beautiful prose and attention to detail in scene after scene — and I was thinking: this is dull as rocks. Who cares what the texture of the curtains was? But now I realize that to other people, those details were painting a picture they could live in, while I only saw it as needless fluff in the way of a good story.)
Ever since I discovered this thing, I've been trying to figure out how I want to deal with it in my writing. I would never go so far as to call it a disability, but it's conceptually similar to my wife's issues with balance: you can either force yourself to mask the situation, or embrace it and redefine life in that context. Should I put extra effort into painting pictures I'll never see? Or should I cut (what I perceive as) the fat from my prose to represent a truer version of me?
The spot I'm at now — and it's already changed a few times already — is to say I'll just keep doin' what I'm doin', with an eye towards using my style to my advantage. Which is to say: if I suddenly start describing a scene in great detail, you can assume that I'm either trying to draw out a moment for dramatic tension, or that I'm sneaking in a detail that is Very Very Important — or that I'm playing with your assumption that either one of those is correct, and wildly misdirecting you :)
So that is aphantasia. If you have it too, congrats! You're a mutant too! If not, don't feel bad. I'm sure you'll develop some other kind of super power, like being able to taste thoughts or whatever.