Can be about yourself, can be about someone else, can be about anything, just try to keep exposed PII to a minimum. Can even be multiple, really.
My favorite one is about the time I hijacked a Geometry Dash forum when I was 12ish years old. Geometry Dash was my middle school hyperfixation, and I was really passionate about it, even though I sucked ass at both the creative and gameplay-based portions of it.
So I found this forum (it was, like, semi-official, IIRC) and began integrating myself into the site culture. I immediately attempted to organize a creative collaboration, and around the point where I got like three or so users to bite, I somehow roped in a forum moderator, who I convinced to rope in the one active forum admin, for some reason. I want to let you all know that at that point in time, my goal wasn’t to take over the forum, but to attach my name to a creative project, even though I sucked ass at making levels, for being the idea gal. Unfortunately, this meant I had to actually make a portion of the level, which I somehow had to bullshit my way out of.
So, over around a 6 month period, I would sporadically post ‘updates’ in the direct message group of cherry-picked, cropped screenshots, while everyone else also did the same but with more consistent progress. I would also use that group DM as a general social output, because lonely socially awkward 12-year old who was iPad-addicted and blasé about internet safety. The project eventually came to a standstill, as most of the people had other things to do and this was not the highest priority.
One day, a pinned announcement thread by the inactive forum admin announced that the active admin had stepped down and went no contact, and they would resume activity for a brief period while they found replacement staff for the forum. Me, being an insane 12-year old desperate for some kind of influence over people, DMed the admin with an inspect-elemented screenshot collection of the group message on the forum where I had the forum admin talking to me about admin duties, and ‘off-handedly’ remark that I’d make a good admin, and then ‘off-handedly’ remark 4 months later that they were probably stepping down soon and were considering who to replace themself with, to which I ‘jokingly’ remarked “me lol” and they ‘sincerely’ replied “honestly, maybe, it’s not off the table.”
This exchange was entirely fabricated. However, the fact that I was publicly listed as creating a collaborative project with them was enough proof for the relatively-detached temporary head admin to believe me, so they stepped away and granted me admin because what was he gonna do, contact the person who went no-contact? So, I was appointed as the head admin for the forum, and in my boundless reign of two whole days, I used my god power to appoint all my friends as moderators, ban people who questioned me, and create pointless boards and stickied threads that had absolutely nothing to do with Geometry Dash.
It wasn’t even forum user outrage that got me removed, I got bored after two days and Skype-DMed the inactive admin that I was actually trolling and didn’t expect to get this far, and somehow he didn’t give enough of a shit to ban me? Did lose admin roles, though I don’t believe I lost some of the more facetious user-flair roles I had created for myself that, while they didn’t give me any privileges, were higher up on the hierarchy than mods, so they couldn’t ban me, and by the time they found a new admin, the whole thing had blown over and I got away scot-free 
I did not learn my lesson immediately set my sights on creating a fake persona as a ‘social experiment’ with a group of good-but-gullible players ‘assisting’ me in the idea of creating a fake person who was a ‘prominent and skilled player’. I got bored a month later and abandoned the project. I have no fucking idea how I got away with any of this and still maintained any semblance of credibility, but it’s the coolest thing I’ve ever done online because I was a literal child when I did it and they were mostly adults. If I didn’t have my moment of reckoning that sent me straight-leftward I know my ass could have very well been doing crypto rug pulls and possibly getting away with it.
What's the 'one story' for you?
) and maintaining emotes, I'm a hobbyist 
JPEG in my Documents folder
and italophobia 💔 
every time something hit.