Do girls like it when a guy knows things about a girl
depends. if its cute things he just notices, then yes. if its personal things he knows from facebook stalking her, its creepy.
It all depends on how cute u guys are
no they don't like it....they love it, it makes them feel special even if they dont like you but little things that you notice not stuff that someone told u or something u found online just something that you notice :)