reminded me of this great piece of writing advice from Simpsons writer John Swartzwelder:

" I do have a trick that makes things easier for me. Since writing is very hard and rewriting is comparatively easy and rather fun, I always write my scripts all the way through as fast as I can, the first day, if possible, putting in crap jokes and pattern dialogue—“Homer, I don’t want you to do that.” “Then I won’t do it.” Then the next day, when I get up, the script’s been written. It’s lousy, but it’s a script. The hard part is done. It’s like a crappy little elf has snuck into my office and badly done all my work for me, and then left with a tip of his crappy hat. All I have to do from that point on is fix it. So I’ve taken a very hard job, writing, and turned it into an easy one, rewriting, overnight. I advise all writers to do their scripts and other writing this way. And be sure to send me a small royalty every time you do it."

I use this technique for my work writing, I first read about it as "vomit draft". When you give yourself permission to write a truly vomitous first draft, man it's easier. Even if you completely rewrite it, it's a fantastic way to get your thoughts in order.

"In most projects, the first system built is barely usable....Hence plan to throw one away; you will, anyhow."

Fred Brooks, The Mythical Man-Month

See also Anne Lamott's theory of Shitty First Drafts.

The idea that an author would just sit down and write a novel starting from the first line seems alien. Like a film not getting made because the director obsesses over the opening shot. Seems like a detail that should fall into place only once much of the groundwork has been laid.

Serial fiction has always been a thing. Most novels 150 years ago were written for magazines. Only in the past century did the write a novel as a complete book really take off. Even then though, authors often wrote trilogies where you wrote a third at a time. (publishers like this because people hooked on the first book at the library or discount store would buy the second and third at full price when it came out). Now in the web world a lot of great authors have figured out that patron and doing a chapter a week (or some schedule) is the most profitable way to write.

Amazon is getting in on the serialization game as well. Kindle Vella is about to be launched. Writers can release stories a chapter at a time, and charge a fee for each one after the first few chapters, which are free.

My wife has been writing in preparation for it, already has three chapters written and intends to have at least six when she launches. I've helped her come up with some ideas for it, and been her sounding board.

I was intending to write for it myself but I haven't quite landed on an idea I think could work in serialized form and I feel compelled to write yet.

Related to your point, George C Scott apparently didn’t want to film the opening scene of “Patton” because he thought the movie wouldn’t live up to the scene. It really gets at the heart of what the whole movie is about and I can’t imagine it without that opening. Apparently they filmed it at the end of filming.

https://en.m.wikipedia.org/wiki/Patton_(film) (The opening scene under “production” - sorry on a mobile device)

Ray Bradbury did this with Farenheit 451. He did a small demo with all the key aspects and then made the novel.

You can do a lot of these small "demos" or short stories and save them for a future novel. Or instead write them together and make an anthology, like the Poe stories.

We need more anthologies.

Vonnegut does this a lot too - toying with an idea over and over again until he feels it is fully explored.

Ironically, the first time I remember being struck by an opening line was from Something Wicked This Way Comes by Ray Bradbury:

"The seller of lightning-rods arrived just ahead of the storm."

It's almost too forward — but I loved the visual. It's hard to not be hooked by the impending storm.