In defence of the weirdo posters:
The brother of a friend of mine has quite significant brain damage from birth and another episode a few years back. He appears to be normally functioning if rather annoying, but he’s got major problems with comprehending people and relationships, and remembering stuff that you’ve told him. Quite unsettling actually when you find out how bad it is because at first he seems relatively normal.
Anyway, he’s always friending these ridiculously ‘hot’ and possibly made up people on FB and talking as if he has been having a relationship with them. Mostly they are of the ‘please talk to me my darling, I just want to know you’re ok’ variety as they’ve blocked or de-friended him.
There must be enough people out there with similar issues to populate the FB pages of famous people.