I would take a guess as to how you really got CUD as your name, but I'm not a maggot who spills other people's personal info on the internet unless they've already done so.
It's not related to my real name, everyone seems to think that and I can see why but it's just not the case. I think the nickname originated when I was in primary school playing Worms on N64 at a friend's place, it had a random three character name generator and I got CUD...Somehow after that the nickname stuck with me, my friends from high school and my brothers will still call me CUD but other than that I've been using it as my gamer name/username around the place for quite some time now.
So yeah, the similarity to my real name is just a coincidence.
That's the story of how CUD was born.