I have identified a class of person that UNNERVES me, and I call them the EUNPC, or, the Emotionally Uninvested NPC.
Have you ever entered into an argument in earnest, only to find that the other party doesn't care if they are wrong; that they might not even care if they are repeating lies? They just insouciantly move on to another wrong argument. Over and over. They never lose the argument, because there were never having an argument on honest terms.
These people chill me to the bone. I feel like I am talking to a hollow being; a low-level devil.