I LIVE WITH GHOSTS
I'm constantly thinking about periods in history I'd like to write about. But it means a lot of research, trying to get the culture right, figuring out how the people lived and thought, and finding all those little things that makes the time come alive in the pages of a novel. No matter how hard you try to get it right, you always miss something. I've found this in reading novels set in historical times I know something about, invariably something's not right.
Writing about the future has another set of problems. Science Fiction needs science that is feasible. At one time I knew more about science than I do now. Things change so quickly, what was thought to be fact quite often is disproved, and what was thought impossible is discovered to be fact.... at least for a while.
So I write Fantasy.