Have you ever encountered a person who hated/disliked you for no reason?

There was one guy named Scalzo back in my military days. I stood up for him and saved his rank when he went before the CO, but for some reason he got it in his head that I’d wronged him, possibly egged on by somebody, I’m guessing. Anyway, he would just glare at me, and finally a couple of people told me that he was “out to get me”. Tried to talk to the guy but just got stony silence and more stink-eye. I finally told someone (who warned me again) to tell the guy to put up or shut up, and then cut a two foot length of 3/4" steel pipe, wrapped one end in electrical tape, and slept with it for the rest of the deployment.