A long time ago, 20 years or so ago, I worked in an office. We got a new receptionist who at first was nice enough, bit bland maybe but seemed like a normal enough to get along with. About three weeks into her employment, the previous receptionist, who had left, got in touch with me to ask if any of the old crew wanted to go for some drinks after work. I asked around and about 4-5 people said they’ll come.
As the new receptionist had never met the old receptionist, it simply didn’t occur to me to ask her to join us. It wasn’t malicious, we were a very friendly office in general. When she heard about our drinks she went completely mental and took it as a some kind of great insult. After that incident she was awful to me, her demeanour changed completely, she got snide, made barbed comments, didn’t pass all the messages to me and managed to turn few of the older employees against me. I found out couple of years later that she had spread false rumours (apparently I was after their husbands) about me behind my back.
All this because she wasn’t invited to a meet up. Which was not nothing to do with her, she had been five minutes at the company and there were remaining 80 people who hadn’t been invited either so it wasn’t the case of her being singled out.
MM’s nuclear behaviour reminds me of her. Back then I was so naive, I had never come across anyone like that before. Someone with a complete personality change after a fairly mundane “incident”. I thought we had made up after me apologising 🙄 but she was on a war path from then on.