I don't think I have ever signed up for a forum etc with my real name. Certainly not my full name, anyway. My surname is too unusual and coupled with my first name I firmly believe I am the only person on the planet with my name. (When I get married next month and double barrel I WILL be the only one.) So I guess I am a bit paranoid.
Anyway I have had a couple of usernames in the past, three actually. I started with Medea, but changed it when the association was... reminding me too much of why I chose it. Hell hath no fury and all that stuff... Anyway, then for a time I was Rosepetal, but when I signed up for a Robin Hobb Forum I went with The Lady Patience as a character from her books. And it stuck.
I guess when I started here I counld't be bothered to type The Lady Patience, so just went with Patience. I like the name. It fits and won't ever pick up a bad connotation. Although I did have to tell a few people I was called Patience BEFORE the Take That song...
Sorry. I am totally rambling. Somewhere like here I don't necessarily thing you need a moniker, but I suppose you don't know that till you have signed up and stuck around a while. If I rejoined now I would be Bryony.