Lately I've found myself having the same tetchy conversation with people over and over (all the while being annoyed with myself for being annoyed why?! what does it matter?) about what's actually involved in writing. Unrelentingly, people bring up “inspiration”, and “the Muse”, and “writer's block” all of which are myths. Total myths. None of them exist. People say, “Oh, you need to take some time off and get away to find your inspiration…” No, I need to get back to work. Or “You just need to find your Muse…” There is no Muse, and she's not going to do the work for me; there's only me.
There are, as far as I'm able to determine, only two things that make writing (or, I think, any art) possible:
- Relentless commitment to mastering one's craft (which requires not just constant learning, but repeated relearning); and
- Working your ass off.
The wonderful screenwriter Aline Brosh McKenna (The Devil Wears Prada, Morning Glory, We Bought a Zoo) had some fantastic comments to this effect in The 101 Habits of Highly Successful Screenwriters. She definitely sees things my way.

I believe that screenwriting is a discipline that requires practice. That's how I learned by doing.
I wish I had rituals like other writers. But I have found over the years that there's no summoning the muse, there's sitting in chairs.
I wish there was something that made the cursor go by itself but ultimately it's all about sitting in the chair. You just have to do it. You just have to keep doing it, and you just have to print it and read it and keep doing it. There are so many things that are more enticing than sitting in the chair, but at the end of the day, that's what you need to do. It's the essence of the job.
I always say it's like having homework, like having had a term paper due for the past twenty years. Sometimes you have great days where you write eight amazing pages and other days you have to cut seven of those pages. Which is why this intimidates some people and makes it somewhat of a mysterious process. You don't really know what it's going to take to get there. The only thing I have found that works is to show up with my hammer and nails and just hammer nails all day.
In a strange way, I feel it's all writer's block. I think your brain would rather sit on the couch and read the newspaper or watch TV. It's all about saying, “I'm going to sit there and I'm going to write, but it's hard.”
Someone once said to me the equation for good writing is ass plus chair. It's all about sitting down and doing the work.