I acquired a nickname with the word "Dangerous" added to the shortened version of my name way back when in the bad old days. Something about being able to survive three major motor vehicle accidents within the space of two weeks relatively unscathed.
It followed me wherever I went (to the point where my new job heard about me before I even got there-- "So, why do they call you dangerous?") and it eventually grew on me.
So, one boring evening in 1996, I jumped online and joined an IRC channel my friend told me about and I had to pick a nick, so, figuring that there were probably a couple dozen people wandering around with my given nickname, I'd use a variant that had popped up recently (at the time), partly due to the popularity of a certain "copier guy " skit on SNL.
"The Dangerous One" became DngrsOne (we were limited to eight letters back then) and eventually Dngrsone. It turned out to be unique on das intarweb and I have been haunting it for nearly a decade already.