Fabnesia
Pretending that you don't know every single detail about a Facebook Friend's life so that you (a) do not seem like a stalker or (b) have something to talk about. Also an antidote for friends that over-share on social media.
(1) I had to feign Fabnesia when I was talking to my old girl friend so she thought I wasn't checking her out on Facebook! (2) If I didn't have Fabnesia, I would have had nothing to say to him!