Private? That is very much not how I see myself (and it is probably not how people see me who communicate with me mostly online). It tends to floor me when people say that. I think the misconception stems from people mistaking indifference for resistance. I am not more resistant to people getting in my face; I am simply more indifferent... to those who don't.
Once again, it's underwhelment masking as overwhelment. I am drawn (when I'm drawn) to people who are more intense than the norm, more emotional, more over-the-top, and often more needy. Interaction has to simply sizzle. Normal interactions tend to pass below the threshhold needed to... to stir up anything at all in me beyond the intellectual awareness that, hey, there's another human in the vicinity. The irony is if that person had been more in my face, they might have broken through that false veneer of privacy. Some people have created strong bonds that way. The illusion of privacy is more apt to vanish if you're the kind of person who (marvelous in my eyes!) can't contain your energy within your own borders.