Mine is from probably about 10-15 years ago!
Basically, I was reading a book (Flight of the Dragon Kyn) and I saw something in there that was quoted as being from "DragonBok" and I couldn't ever figure out what that was. I remember even trying to look up what a "Bok" was. I had no idea. So to me it became a mystery, an enigma of sorts. So since I was young and wanted to be all MYSTERIOUS ON THE INTERNET, I chose it as my moniker
P.S. Turns out it was a typo for "Dragon Book" so really my name is a typo D:
P.P.S. I also like to say that "When I'm around, everything will B-O-K"