A confession about confessions: I don’t like them.
This is why you’ll see few overshares from me on this site, not that overshares are necessarily confessional, but rather because I fear making them so, and so just sidestep the issue by doing very little sharing.
Of course, I don’t think of myself as a particularly reserved or cool or even, hell, dignified person in my daily conduct. So let me be clear that I don’t think this has much to do with decorum. (As a side note: Screw decorum. Be deliberately indecorous in your life; don’t follow rules just because they’re there. Follow them because they’re right. That’ll keep you going.)
Hadley Freeman has a piece on this in the Guardian right now that is worth reading. (Though I’m told she was a ghost writer for Victoria Beckham, try not to let that overrule your interest; she makes sense here.)