I love this quote, because there is no questioning the truth of it. A writer is constantly “writing,” even if they don’t have a pen or pencil or keyboard. I constantly am thinking about my stories and writing and revising in my mind. Sure, those mind-compositions don’t always make it to the page, but the point is that I am using my mind, even when I am not physically writing.
I think that most (if not all) writers do this. If we don’t, our stories are flat, boring even. We have to think about them nearly every moment of every day until something clicks and the whole story falls into place. Have you ever experienced that? During one of my revisions of QFS, I realized that my minor villain did not, in fact, know everything about the major villain and was not working with her. The minor villain had a fascinating back-story of his own that shapes every action he takes – and I never would have realized it had I not spent so much time thinking about my story.
So keep thinking, keep imagining, keep writing!
Take care, fellow travelers.