Clearly, professional writers operate on a different premise than those of us who hope to be.

Quantity is not an issue beyond standard practice for the genre in play. A self-imposed quality is.

I'm going to venture a guess. David spends little time worrying about where he will find his next word. He spends little time worrying about where he will find his next 10,000 words.

He spends his energy telling the best story he can. Story tellers find the words. Or, maybe the words find the story teller that is looking for them.  My guess, before you are a professional writer of fiction you will be a story teller. I'm just guessing here.