I've only one to date, and I don't know whether I say that thankfully or otherwise about that number, but I am definitely still utterly ashamed 10+ years later, that even now as a grown person who can admit heavily embarrassing things, that one username is one I cannot get over (hint: although I blame it on the biology class the day I chose it, in attempt to have a unique one), to the point that I actually had someone ask me why I chose it a couple of years in.
Ignorance is bliss they say, and that was truly so back in the day.