Bobbin is my go-to when I'm naming myself in a game because it's a tool used in sewing and weaving that I think sounds nice as a gender neutral name too (if I get too nerdy about it I think of the character as a vessel and a tool for creation, so the name fits symbolically)
My pre-teen self actually put some thought into it and came up with the name I've used pretty much ever since. Minerva for both the awesome Prof McG and the goddess, and 'maga' as a feminization of the Latin 'magus'. I've used it for so long on the online community and have so many friends who know me by it that I respond to Min or Minerva just as easily as my IRL name
When I was younger, I had a phrase where I just typed in random words and google translated them to see if it sounded cool. Quirmzi came from "qirmizi" which is red in Azerbaijani, since red's my favorite color. I, being the responsible child I was, didn't think to write it down, so I messed it up when typing in the username for a game I use to play. I decided to just roll with it, so here I am! The sad thing is that no one can pronounce it though.
My friends nicknamed me "Jello", so I was known as jello279 on a bunch of web games/online rpgs. Eventually, on social media as well!
I wanted a name change a few years later because the numbers felt unnecessary. Brainstormed a bunch of names and had some people vote. Now I usually go by jellobeanartist (or simply, jellobean if its not art related) :D
I also go by jolijello sometimes because it's both part of my name and french for lovely/nice. I love fun words things like puns and alliteration.
My current username comes from an enemy from a jrpg I liked. It's literally the one in my pfp. I had one other username that I used alot, it was Gageeker. It's a combination of gamer and geek as I wasn't very good at making up names.
I've had a lot of different usernames but "Neverbell" is probably one of the strangest yet simplest when it comes to its origin. I was loading up a Minecraft modpack and it had a custom home screen with a server hosting service accessable from the main menu. Out of random curiosity I clicked it and it gave a random server name: Neverbell. I thought it sounded cool so I started using it for some accounts.