Dark Tuesday.

An M.I.T. professor called Sherry Turkle had an op-ed in yesterday's "New York Times," which I think is worth reading. It's titled "The Documented Life," and questions why we "interrupt our experiences to make a record of them."

I'm sure it's happened to you. You're having lunch with someone who seems more focused on her hand-held than on what might otherwise have been conversation. Or seeing people so bent on taking cell-phone photos that they miss the concert they're taking photos of.

Turkle says, "we text during class, in meetings, at the theater, at dinners with friends. And yes, at funerals, but also more regularly at church and synagogue services. We text when we are in bed with our partners and spouses. We watch our political representatives text during sessions."

We're so busy chronicling the moment that we miss living in it.

All this brings to my mind a generational divide between the world today and the world I grew up in, a world I prefer.

In just one or two decades, we have migrated from "I think, therefore I am" to "I share, therefore I am."

I'm not one to praise the dissolute and drug-addled age I grew up in, but somehow I think "Turn on, tune in, drop out," might have been healthier than "Log on, location on, tweet on."