Would you class a party hosted by that guy who was talking to that girl who was friends with the coworker you went drinking with three Fridays ago as a significant event?

Sure; it's just harder. Although it also depends on who your friends are. It was easier back in the Netherlands as I was living in the city I grew up in and knew people there. I also had a regular (non-remote) job.

Is there a reason to believe, given how little we trust Facebook, that deletion and deactivation are different things? I've built multiple consumer web apps and if there's one rule, it's that rows are never really deleted from a database. Not to mention backups, caches, Google crawls and so on. I'd worry that the naive consumer thinks they can post embarassing content to Facebook, delete their account, and somehow believe it will never be found again.

I'm the other way. I _know_ I miss out of a lot of things I'd know about and be interested in attending if I had a FB account still. And I'm still happy with my choice not to be there. There are groups I've lost touch with, because they no longer bother running a website or mailing list, and do everything through FB these days. Even groups I'd have bet money on _not_ going that way (looking at you, DorkBot Sydney...)