I’m gonna have to go look up the writing book where I first encountered this advice, because it’s escaping me right now, but the wisdom went something like this:
The quality of your writing has no correlation to how you feel about it while you’re writing.
That’s right, no matter whether you’re happy or sad, angry or depressed, jubilant or hungover, your emotional state does not correlate to the quality of the words you’re writing.
I’ve had days when I’m a miserable grump, and write a great scene in spite of myself. I’ve had days where I’m depressed and write crap.
I’ve deleted scenes that I thought were brilliant and which I wrote in a burst of inspiration. Oops.
I’ve had good days and bad days and everything in between. The quality of my work stays consistent—and (I hope) actually improves with time.
Will it be easier to sit down and work when you’re in a good mood? Of course.
That’s why taking care of your health is so important.
But you don’t have to be in a good mood to work.
As a professional, you go to work no matter how you feel. Do you want to be a pro? Then get to work.
This fetish with the flash of inspiration is damaging to the working writer. It gives the wrong expectation. How can a writer not be disappointed with a bland day when they expect genius at every turn?
In the end writing is a craft. And like the woodworker goes to the shop every day no matter how he feels about his work at the moment, so must the writer.
Otherwise how are you going to get enough practice to be any good at this thing?
Are you going to wait until inspiration strikes?
Are you going to wait until you’re “in the mood”?
Nope. The time is now. Get to work.