I usually use the username Master-con(sounds weird now) a while back as a username for anything I joined in.When I was about to decide my TBT username,I didn't want to add the "on",so I just went by MasterC.
The JJ = My Brothers name also starts with a J so we named out AC Character JJ for (Josh & Joel) and then I joined TBT, But I couldn't do the username JJ so I just called it "The JJ", Too smart.
And Josh is my real name, But most people call me Joshua.
Oh wait, Those are my relatives who call me Joshua :S
It was an old nickname from 4th grade. I used to bring my lunch everyday, and I almost always had a Twinkie. So some kid thought of that name, and I have always used it since.
I chose mine because it's the same name I use on Youtube. The jvgs stands for Jeff's Video Game Site and then Jeff is my name. I know it's a bit redundant, but the name jvgs was already taken when I joined Youtube, so I made it jvgsjeff and the name kind of stuck.
Mine comes from an old webcoming that has been going for well over ten years now. It's a Metroid parody where Samus and the 'gang' are trapped on a planet called ZR388. Since SR388 was a little.. obvious, and that was the first IRC I joined, I decided to take the name ZR388 and it's been mine ever since. I don't think there's anyone else on the internet that goes by this name... Works for me.
Thousands of years ago, before the age of Industrialism, before the world was even shaped as we now know it, there was a wizard. This wizard is as unto me nameless, and therefore impossible to find on Wikipedia or Facebook, but he for some as of yet unseen reason used his powers over the forces of nature itself to send me my online name through time! It could have been a curse, a blessing, or an attempt to order a supreme pizza, but the name has stuck ever since I first used it on the old Nintendo Nsider forums... Actually might have even been before that.