I've experienced so much of this, and it confused and frightened me as a kid, and it still does as an adult. I've especially encountered it in the workplace. One woman was incredibly friendly to me, very complimentary, shared her personal life with me, sought my opinion, seemed to advocate for me at work...then she started having little issues with how I communicated, and there were misunderstandings. When I asked for clarification via email, then saw her at work the next morning, she flipped out on me in front of everyone, said I had "a lot of negativity," and claimed it was really affecting the rest of "the team." She said a bunch of other stuff, too. When I asked her why not her or a single person (I thought I got along fine with everyone there, truly) had said any of this to me, she claimed "they" were all "too intimidated" by me. ?! Actually, nobody else had a problem with me - just her - she was just trying to make me paranoid and insecure (and it nearly worked). Although she took credit for my hiring, she now said she NEVER had wanted to work with me, and was still pissed at me for something that happened three years ago. (?!) Oh yeah - and we were NEVER friends.
I'd truly thought we were friends! I thought if she shared her personal stuff with me, I could share mine with her. NOT!
I realized the last six months of my employment there had been a lie. I had to quit, because she was sort of in a supervisory role, and even though she's had a history of "incidents" with other employees, I knew nothing would be done because they'd never find a replacement for her who'd work her hours for such measly pay. And sure enough, nothing was done. I thought there might be some justice, because the director asked to speak to me in private, and was very supportive and said something would have to be done. But later I realized SHE was just playing me, too - she just was checking to make sure I wasn't going to try to sue them, or something. She turned out just as two-faced as the crazy coworker. It's good that I left.
But it's so frustrating! People confuse me SO much.
To be fair, this person had exhibited a history of slightly nutty behavior, but like an idiot, I thought if I was friends with her, she wouldn't turn her crazy on ME. Boy was I wrong! I won't make that mistake again (I hope).