I've always been shy. To this day I find it difficult to talk to strangers face-to-face; over the years I've learned to do it reasonably effectively when necessary, but I'm still queasy in an adversarial situation. Large groups also freak me out, even amongst people I know --- two weeks of constant social contact with Mozillians just about exhausted my social energy. At least with technical people I don't have the confidence issues I have with other groups.
And yet, it doesn't seem to bother me getting into conflict situations on-line, when that's necessary. It's probably the Internet making the other person seem less than real. Overall I think that's a horrible feature, but it works for me here I guess.
I'm just thinking about this as I grapple with my fear of having to interact with car mechanics, while I'm not afraid to take on mega-corporations :-).