It's a question writers are often asked, and which they may sometimes ask of themselves. For my money, Stephen King provided the best answer to this question. He proposed the idea that we all have a filter in our brains and as we go through life certain things stick in that filter, things which may pass through everyone else's. For King, the things which seemed to frequently catch in his filter erred on the darker side of life. Hence the horror. For other people, their filter may catch the weird and the amusing, the fantastic, the mysterious or even the downright saucy.
I've found that I tend to write about the extraordinary, sometimes the fantastical, but my stories are always grounded in the human experience. After all, a fantastical tale told without any emotional human connection is really just an empty exercise, in my opinion. I also tend to write about tortured heroes. I like a happy ending as much as the next guy, but my protagonists need to go through a pretty ha...