Oh, this is such a good question! There is zero chance I'll be able to answer it succinctly, but man, I'll do my best.

Yes, I do completely finish all of my fics before posting them, including my long projects. There have only been two exceptions to that in the 20+ years I've been writing fanfiction, and I'll talk about those below. There are four broad reasons for this:

I can't handle the pressure of knowing people are waiting for an update.

I receive enough dopamine from the act of writing that readers' comments are a bonus rather than the goal itself.

I struggle with broad narrative structure.

Relying on others' actions to motivate me is very unhealthy for me, and I've actively worked to avoid it in my adult life.

I'll also preface by saying (though I'm sure everyone's already realized) that this is what is true for me. The truest writing advice I've ever heard is that no advice works for everyone, so please understand this is descriptive, not prescriptive.

1. I can't handle the pressure of knowing people are waiting for an update.

There are only two fics I've ever posted as I've actively written them. The first is River Stone, which I first posted anonymously on the DA Kink Meme in 2012, and the second is Metamorphose, a Thanzag three-part character study from 2023.

River Stone was a prompt fill, which meant I knew where I was going with the plot, and as I was drafting out ideas, I felt secure enough in my chapter structures that I felt okay updating the kink meme as I went. I had originally intended the kidnap arc to take a lot longer than it did; I wanted the relief of Fenris's rescue to be visceral for the reader as well as Hawke.

However, around the second posted part of that section, I started getting comments saying that rescue was taking too long; you can see them in that link above. This made me panic that I'd lose readership if I stuck to my original plan, so I truncated the trip, had Fenris show up much sooner than I'd planned, and ended up posting writing that I was not happy with either structurally or technically.

I've long come to terms with that, and I polished up the parts that most bothered me in the transition to AO3 (and am very proud of that fic regardless), but that feeling of dissatisfaction at caving to pressure and writing something I felt was substandard stuck with me for many years.

Then, in January of 2022, I got really into Hades. I'd already started a different Thanzag fic & been pleased with it, so I thought I could easily tackle a three-part character study of their relationship as framed by the River Styx. This kind of writing was my metaphorical bread and butter, and it'd been ten years since I tried posting as I went; surely it was time to see how much I'd improved & recognize how much easier it was to post concurrently with the writing.

It took me over a year to finish the third chapter. Even worse, I could feel myself getting upset every time I thought about it; a comment would come through my email and I would find myself literally wincing as I opened it, afraid it would be on this story. I started avoiding AO3 notifications altogether—because of one fic! One fic, among the 80 or so I'd finished!—and when I finally sat down after fourteen months to knock the darn thing out once and for all, it was with a sense of immense pressure and guilt and a desperate need to just be done that again spurred writing that did not actually please me or relieve the stress.

They were both such singularly unpleasant experiences that I've never wanted to repeat them. Maybe in 2032 I'll try again, just in case—but maybe not.

2. I receive enough dopamine from the act of writing that readers' comments are a bonus rather than the goal itself.

I know this is probably the most subjective item on this list, but it really is true. It helps that I have a lot of hobbies at which I am very mediocre; I learned pretty early that sometimes the things I spent my time on would really just please me alone, and I had to be okay with that to continue the hobby.

Writing is definitely one of those things, even though I've certainly worked much harder on honing the actual craft there than others. I wrote a lot of schlock growing up, but man, I had such a good time doing it! That enjoyment was enough for me as a kid, and for whatever reason, I was able to carry that forward into my adult writing as well.

the statement is delivered in a direct yet cheery tone as if you were expecting to hear it, even though the person saying it is a complete and utter stranger to you.

"excuse me?"

"you've got an eyelash on your cheek," the white-haired guy repeats with a beaming grin, tapping his finger against a spot on his own cheekbone that you figure mirrors the location of this alleged eyelash.

from the few but notable stories you've heard from the host of this party, your coworker-turned-nearly-friend shoko, you'd guess this is satoru gojo.

you brush your fingers against your cheek, hoping it won't smudge your carefully-applied Halloween makeup.

you were conflicted about attending this party in the first place, given that shoko has been working with you for all of three weeks. the bar you call a workplace is more of a 'we're all family' sort of establishment, so you felt your attendance was expected instead of anticipated.

you'd even been talked into putting on some pink and blue detailing on your face, tacking on a pair of dollar store wings over your black dress to go as a very low-effort butterfly.

still, as last-minute as your costume choice was, you hope you haven't destroyed the minimal makeup on your cheekbones.

"did i get it?" you ask, deciding to trust this assertive stranger's judgment.

you give him a once-over, still unsure how he even noticed an eyelash on your cheek from several feet away.

he's wearing all black -- dark jeans and a loose black button-up, sunglasses that he's wearing even though the only light sources in shoko's apartment are a few lamps and a disco ball in the corner. though, to be fair, he's mostly looking at you over them, his eyes almost fully visible over the rims.

"nope," he answers in a tone nothing short of perky.

a pause. you attempt again.

"now?"

"nope," he repeats, grin reaching his icy blue eyes. "want me to get it?"

you open your mouth to object, but find no reason to. he's a stranger, a bit over-confident, sure, but no reason to distrust him.

"please don't smudge my makeup," you answer by way of confirmation.

somehow his smile grows, and he closes the distance between you, reaching up a hand to graze his thumb across your cheek.

he lingers, the pad of his thumb trailing soft enough to not disturb any of the blue-pink streaks but you can still feel it, a trail of soft heat following the movement of his hand.

goosebumps prickle on the back of your neck and you step back, surprised at how close he'd gotten --

-- or was it you who had bridged the gap?

"so who are you supposed to be?" you blurt to fill the silence, "your ... costume."

as soon as the words leave your mouth, you're not even sure it is a costume. there's nothing particularly distinctive about it, except for the parts that are entirely him -- the hair, the eyes.

the personality.

he steps closer again, and you don't move back.

"not a costume, really," he grins. "last minute invite since i just got back into town."

"that's not very festive," you mumble, barely audible.

he hears you.

"you'll have to forgive me, 'because you still need to make a wish."

"hm?"

he holds out his thumb.

"eyelash, you gotta make a wish," he insists.

against your better judgment, you dip your head in and blow, soft gusts of breath blowing the invisible eyelash into the stuffy party air.

"excellent," he beams. "what did you wish for?"

Cool, cool, cool cool, cool, cool cool cool...

Received my support ticket this morning so if I don't hear back after Chapter 2 has been beta-read, I can politely bother them again. There is definitely time to get this sorted, and I'm in no way the first person this has happened to, but even so.

Oh god. You've struck me down, that's so cute

I'm just imagining Itty bitty twin bros, sneaking into some bounce area, the area deflates and Stan, being Stan, tells Ford to just go jump without him. It'll be fine! He can jump pretty good by himself already!

Cue Ford hesitating, seeing baby foal Stan stare longingly at a bounce house, and then he scrambles off to find a solution with all the seriousness of life or death. He needs to figure out how to get Stan on a bounce house, his brothers happiness is at stake.

Then fuzzy socks to the rescue, and the two of them happily bounce together until the people in charge see the two of them and chase them off, giggling.