My comment at the time was that this is true and not true. On one hand, yes, each thing you write is its own adventure and requires its own process. But on the other hand, you do learn some things as you go along. If you've written a novel or two, you're not starting from zero again with the third one.
But each one does make its own rules. I've written thirteen mystery stories so far, and I'm writing a fourteenth one for the book I'm planning (and, no, not because I'm superstitious). The difficulty is that the new story has to fit into the middle of the book, because it's replacing a story I had before that I'm taking out. That story was pretty good, but it depended on the reader having read the novel U-town, so it didn't really work as a story in a collection. I'm increasingly aware of the importance of having each book stand on its own, even as they all take place in the same world with the same characters.
So, I needed a replacement story, but it needed to do what the other one did, mainly introduce some characters who will be important in a later story. And, of course, be a good mystery story, too.
And this is turning out to require a different process than my usual one, probably because the story has so many things it needs to do. Mostly they just need to be good stories. So, instead of going part by part, posting as I complete each part, I have the whole thing in one Word file (well, Abiword, actually) and am chopping and slicing and reorganizing in there.
You know, the way most people do. 🙂
I started off trying to follow my usual method, but that wasn't right for this project, so I had to adapt.
(The most interesting part of writing this post was reading about Gene Wolfe, who said the original quote and who has written a lot of books – more than Neil Gaiman and me put together and then some. Now I'm curious to read some of his books, since so many people admire him and I'm not even sure I'd ever heard his name before.)
Later: Well, after I wrote the above, I solved my particular problem in a different way. I'm going to remove the later story (the one that required the earlier one be created), plus two other short ones. I've figured out how to do this without causing problems (one remaining story will now need an epilogue), and I think it will make the collection stronger.
And, most importantly, it will make the book shorter (~300 pages as opposed to ~400). The length of the thing has been my main concern all along. ~400 pages is a long book for a collection of mystery stories (even for a novel that's disguised as a collection of mystery stories). But (because it's really a novel) it was always hard to figure out what could be removed, but now I've got a plan that I think will work.