When we quarrel with our loved ones, most of us have the ability not to do too much damage. This is because of something called object constancy. It basically means having the ability to still have a positive emotional bond with someone when you are also feeling angry, hurt, or disappointed with them. It also means being able to feel emotionally connected to that person when they are not physically around you.
To most of us, this is a given, and we can move past the little things. However, to those with narcissistic personality disorder, or people who are psychopathic or sociopathic with narcissistic traits, the negative feelings they have towards someone in the moment are all they can focus on.