(I've explained this before, but I might as well explain it again).
I created this nick as I wanted a semi-original and decent nick for use on this site (and other places). My previous most creative name up to this point was ehgames1234. Which, naturally, sucks (and contains the initials of my name).
Thus, I combined two of my favourite characters from games (at that point in time) to create a name: the Black Mage from Final Fantasy (specifically the FF1 breed) and Mario from the Super Mario games. I then created BlackMageMario.
I have a second name I use occasionally on IRC: BadMusicMurder. This one comes from a funny story that occurred on #smwc (I unfortunately never kept logs of that though). Basically, VinnyBoiler stated that my initials, BMM, stood for BadMusicM, a reference to AddMusicM. I went the full Monty and changed my nick to BadMusicMurder. I've kept it for at-least a year now, and if I ever do change my nick it'll be either to BMM or BadMusicMurder.
I chose mine because Eevees are adorable and cute and anybody who disagrees is wrong. They are my favourite Pokemon also for the fact that they are unique and because of the many evolutions, it's very easy for them to fit into your team. I always use them, and in Black 2, I even have a box and a half full of 'em!
I had a period of my life where I was ready to die. I went to a cave, got on my hands and knees, and started crawling. I was going to crawl until I died.
I passed out, and when I came to I was found like a grey ape. He took me home and took care of me. Nursed me back to health.
Already explained a bunch of times, but I'm going to do it again.
Well, I tried to make a decent name, so I lurked everywhere, and found a list of Pokemon names. I found a boss named Archie, so I decided to come up with that (it was before I knew that there was a boy named Archie that was in the comics). I've been sticking with it regularly and am probably going to stay with it for life, unless I decide otherwise.