I almost never use the same username in more than one place and have always liked changing my handles on whims. Who I am as a person is in flux and being stuck with the same label in all places at all times goes against how I see myself. Something I appreciated about IRC is I could instantly change my handle as I felt like it; when I take extended breaks from communities like forums, sometimes I feel more comfortable returning with a new handle than picking up an old account who reflected the kind of person I was months or years ago vs the kind of person I am now. Japanese BBS are more accommodating to this kind of feeling ...
Seeing all the people here talking about names they've been using for years or decades is appreciable. There is some value in making a brand of your handle, so to speak; it can make it easier for old friends to find you and reconnect after time has passed!
An added benefit to using a multitude of names is that it makes it harder for bad actors to keep tabs on me.
This name "rancher" was picked because I was feeling like a cowboy when I stumbled across this forum.
I came up with my current username almost a decade ago, trying to replace [insert cringey old username here] with something halfway better. I had recently hacked my Wii and gotten whatever games/emulators I wanted to run on it, and had just finished Sin and Punishment on the N64 Virtual Console when the credits started with this:
GLASS SOLDIER.png (248.66 KiB) Viewed 24 times
The in-development name for one of my very favorite games became my own name. I usually just go by "glass" for short these days, though.
...Only problem is that when I'm in a call with someone and they say "glass" in any context my ears will perk up as if they said my name even though they didn't. Don't name yourself after an everyday object.