I tried to write a physically correct flat-Earth story. So the fantasy world is flat, and people interact upon it like they would on a flat Earth.
I ignored some things that just didn’t work or handwaved them away like gravity. It’s a magical world, so the gods made down point down.
The problem is, some things are so alien to the real world, I keep slipping. Things like seeing long distances. From a mountain, the characters can see all other mountains at least sometimes, and dawn moves all weird.
To simplify things, I tried a geocentric world, and now it takes me fifteen minutes to figure out how the phases of the Moon work.