This might be the way it is for everyone else, don't ask me. But the stories that I write, or might right, first come together in my head. Maybe not every detail, but they exist first in my head. Making stuff up as I go rarely works for me. So the story forms in the head, and then sort of bounces around like a piece of popcorn, begging to be let out. Recently though, I realized something. Once I write it, it doesn't really haunt me anymore. As though in writing it, the story has been released. What if that is really the case? If it's true, then maybe sometimes the reason one has trouble writing is that they are trying to write something in particular, when there is another story that needs to be let out first. That doesn't mean it's easy to find out which story to write if you have several, though.