You can't wait for inspiration. You have to go after it with a club.
Jack London

The 'muse.' According to dictionary.com, “...the power regarded as inspiring a poet, artist, thinker, or the like.” Many have written about finding or waking one's muse. A fine science fiction author, who's name fails me at the moment, wrote that when his muse was sleeping, he would still write... write complete and utter nonsence and gibberish.

Heather Armstrong, in her keynote speech at South by SouthWest Festival in Austin this year, said “Keep writing. Keep doing it and doing it. Even in the moments when it's so hurtful to think about writing.”

I would like to add, that when it starts hurting, you have woken your muse. You have found that 'sweet spot'; that transit from soul to words and sentences and concepts.

Writing is not necessarily something to be ashamed of, but do it in private and wash your hands afterwards.
Robert Heinlein