The Writing Life by Stephen King. If you liked his On Writing book, you'll like this essay.
The man is spot on. My muses aren't a flea bitten dogs. They are muses like Somnia from The Inspiration of Insanity. They are many and, so far, they are all female. They flitter, tease, tempt, sulk, slap and ignore. So far, they've always come back to me. They are my wenches and I love them. I have to agree with him on the fact that a good writing binge is better than any painkiller out there. I have forgotten illness, heartache, loneliness, the pain of broken bones and migraines while writing. It's my preferred drug.