tenex
reality-based
A couple of years ago I read of the case of man who had a most extraordinary vision problem. Cutting a very long story short his vision had a hole in it where no image was formed and around it was a normal image. His brain could not tolerate this hole and so searched his memory and inserted images from his memory into the hole. Mostly these inserted images were of stained-glass windows positioned high up in churches in a position that corresponded with the hole in his vision. Of course this meant he had a stained glass window in his vision all the time no matter what he was looking at. I can't remember for sure how this was cured but I think he had some surgery and he recovered some vision to fill the hole and the images of the stained-glass window disappeared.
Filling holes is a major task for the brain. It happens with memory too. As it fails (or when it has gaps) people start saying the strangest things, because they know or think they should remember and will confabulate details when asked and nothing arises.