What Facebook's On This Day shows about the fragility of our online lives

If we're channeling our energy into tweets and status updates, where are we creating anything that is built to last?

Can you remember how you were feeling on this day last year? How about three years ago? Facebook can, and if you're a regular user of the service, you may have noticed that for the better part of the last year, it's been ready to remind you.

"We care about you and the memories you share here," the platform warmly intones, offering a confetti draped image of a photo or status update from some time ago. Theoretically this is a sensible idea - we upload massive reams of stuff to our online networks, and our fleeting day-to-day engagements with these services are easy to forget, and occasionally fun to remember. Sure, you'd like to be reminded that your friend's wedding was six years ago now, and look how much fun you had then! Or look how three years ago you posted about your favorite coffee shop, and now just today you did almost the exact same thing. Ha ha! Good times!