I'm more 'quiet' in real life. I'm certainly not shy, but I would say that I'm quiet. On these forums, I think of myself as a somewhat straightforward poster. I'm also more socially awkward in real life and have difficulty keeping a conversation going.
Anonymity is one of the beauties of online discussions. In real life, people prejudge others by appearances and make lazy judgments based on one's looks, gender, weight, racial ethnic background, religion, clothing, jewelry, hair, etc. Online discussions greatly reduce the potential for these lazy judgments to be made because, unless there's a profile picture, you do not know what the participants of the discussion look like.