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.
It was given to me by my boyfriend, which is amusing, given that he's the *real* bitter one. Whenever I'd complain about anything, he'd sarcastically say "Sigh...bitter!"
This later got expanded to "Sigh, bitter, bitter-girl." And so, when domain-choosing time came many years ago, it just seemed appropriate.