I have gone through phases of deactivating it… I only reactivated it last week actually. Usually I deactivate it if I'm feeling depressed because I spend too much time on it wasting my life… both times for the same reason, both times after I deactivated it I basically just didn't even think about it again. Both time, travel sparked the reactivation - I would meet heaps of new people whilst travelling that I didn't want to lose contact with and Facebook seems to be the thing these days. But actually the cool thing about deactivating (if you can refrain from logging in again) is that it keeps all your stuff, so if you decide you want a break for a few months or a year or whatever you can get everything back afterwards.
I think it would be SO WISE to quit FB during your year 12 year (preferably forever, but it DOES have its uses). You just kinda have to use it in moderation…. I don't post that many statuses (two a week maybe, max) and just kind of use it to maintain a bit of an idea of what old friends are up to… but honestly most of the time its seriously boring as batshit and full of people who I met like 10 years ago a handful of times and for some reason the people I actually give a shit about a) I either see regularly or b) never post anything. Anyway thats my blab. I recommend deactivating it, especially if you're busy. If you're not busy, then boredom will tempt you to reactivate.