It's not just "anonymous" versus "real identity", either. In real life, everyone acts differently with different groups of people; since you're rarely with (e.g.) family and friends at the same time, you essentially have two separate identities, free to develop in slightly different directions. The fact that everyone knows your name doesn't matter if there is no global state associated with a name.
Of course, Circles are Google's attempt to mirror this, although I think they do so poorly: rather than there being a mental "context shift" as in real life, posts from all your circles are mixed together, and you have to decide on a context each time you post. In practice, I share everything publicly because it's the path of least resistance; the result is not much different from Facebook.
Of course, Circles are Google's attempt to mirror this, although I think they do so poorly: rather than there being a mental "context shift" as in real life, posts from all your circles are mixed together, and you have to decide on a context each time you post. In practice, I share everything publicly because it's the path of least resistance; the result is not much different from Facebook.