A condition of thoughtlessness which occurs when you open up Facebook and forget what you are doing. It is usually temporary, and the person will eventually awake as if out of a stupor. Those who suffer from it are unable to retrieve information and instead fall into a state of oblivion. The most common symptom is mental blankness where the victim descends into a deep state of incognizance.
Danny: Dude, can you see what time the open mic is at?
Rob: Sure man, lemme just check on Facebook.
15 minutes later....
Danny: Bro! What the hell have you been doing for all this time?!
Rob: Oh, I, uh...just looking at some pictures of this girl who's a friend of a person I found on the wall of an acquaintance from middle school.
Danny: Broooo! Shit, stop it, she's like 16. You've got Facebook Amnesia! Now go and check the event page.