Hi Amy. What a great question! And my first one, so you get to set the standard. :)
For me, the inspiration wasn't consciously realised. I honestly can't recall exactly when I started writing, other than, around the age of 14, twisting essay titles so I could write my own short stories, much to the chagrin of my English teacher. But I think, once I started doing it, I discovered how liberating it was - yes, THIS gives me a way to purge myself of all the daydreaming and fantasies and stuff I want to share with other people, but if I say it out loud they think I'm mad, or I'm lying...which, of course, much of fiction is just that. Lies. But really elaborate, well-thought-out lies.
So I guess my inspiration was that: to share the stories that were already in there.