What is inspiration?

I have been working on the short story I'm currently writing for MONTHS and it's frustrating me because it is not flowing. I don't know if this is a good thing or a bad thing. When I write, if it's not flowing, I put it away and go on to the story that is insisting on being told. I have put this one aside, and written one other story that sprang from my head fully formed, but I keep coming back to this story. I am intrigued by the people telling me their lives in whispers and half truths and I want to get to know them fully, but they are tricksy hobbits and won't give it to me straight. My beloved liars got me to thinking on inspiration. What is it? Where does it come from? Do we have to wait on it? Or can we access it at any time?

I am not the kind of writer who can get up and write from 6am to 2pm like it's a regular 9 to 5. I have to wait until the mood hits me, until the words are ready to pour out of me. Whenever I try to make myself sit down and write when I don't feel the magical "tingle" up and down my spine what comes out is stale and unworthy. But when I do feel the inspiration, I feel the work is beautiful and special, worthy of other's time and attention. I think this is mostly habit, and partly true. I have told this to myself over the years so many times that I believe it. I know if I just sat down every morning for an hour everyday, something wonderful would eventually come out of it. But I love that special "tingle" that I've divined as inspiration. If only I could bottle it up so I could access it whenever I wanted to write something lovely and amazing.