Yeah, that's the problem. Once I married a woman I had known for six months, because that whole time she was crazy about me. I was the center of her world. It felt great - I wasn't used to getting a lot of attention from women, and here was one literally begging me to marry her. I went for it. But for whatever reason (maybe God thought it was funny) there are people out there who flip between over-the-top loving someone and over-the-top hating him, for no external reason. My ex-wife kept the crazy under control before we got engaged, but after that about a couple of times a week she would flip out. I ended up divorcing her after six months of marriage - the last straw was when on my birthday she flipped out because I wanted to celebrate with my family and not just with her. (She was extremely jealous - not just about other women but about my family and even my dog.)
Normal social interactions don't prepare you to deal with a person like that. Even long after the divorce, I would still wonder if maybe I was the one who had been doing something wrong - after all, she was usually so sweet and loving!