What's the deal with your nickname? How did you get it? If your nickname is self-explanatory, then tell everyone when you first started using the internet, and what was the first thing that made you say "wow, this isn't just a place for freaks after all?" Was it a website? Was it an email from a long-lost friend? Go on, spill it.
I picked up the nickname Mach5 when i was looking for a good tag to play online Quake with. As I like the song, the car, the speed of sound, driving really fast in my beater accord, the word 'mach', and the number 5, i think it fits.