I'm pretty religious about "a place for everything,and everything in it's place," for this very reason. Once something is out of place, it may be weeks before I run across it again, even though I've walked past or stepped over it a dozen times while it was "missing."
Seems no matter how thoughtfully I choose a spot to store something, once a certain amount of time has passed since I put it away, I can't remember for the life of me where I stashed it. Maddeningly, I will often have a clear picture in my mind of where it ought to be, but still continue to overlook it, or eventually discover it in the most logical place I should have been thinking of, but didn't.
When someone else asks me to get something, I also have the problem of being blind to it, if it doesn't quite look like I think it should, whether it's a different color, or even turned upside down, or sideways to the way I'm used to picturing it.
It reminds me of one of the tests the psychologist put me through when diagnosing my autism, in which you're supposed to take these white blocks with bits of red color on them, and reassemble them into the designs shown in a picture. It ought to be ridiculously simple, but I was so flustered by the fact that he was standing there watching me, with the timer ticking, that the timer ran out and I hadn't completed a single one of them. I felt like an idiot. if I'd been alone in the room, I could have done them all in a matter of seconds.
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"I don't mean to sound bitter, cynical or cruel - but I am, so that's how it comes out." - Bill Hicks