I recently watched a fascinating video on psychopaths, which describes psychopathy in terms of attention.
In a nutshell, psychopaths don’t pay attention to the same things that normal people pay attention to. E.g. take a cat: when it sees prey, it focuses its attention on catching the prey. It ignores pretty much everything else. Psychopaths are similar; when they are focused on getting something they ignore other information (the feelings of others).
Narcissists are hypercompetitive. When they compete, their attention focuses on what it will take to win; they marshal all the mental resources they can to that task. Notably unimportant: how others feel.
One fascinating exercise (see the video) asks subjects to focus on images, and ignore the words written on the images. The psychopaths do great at that task; they are able to focus their attention narrowly and keep working towards their goal. In some high-stakes circumstances the psychopaths will outperform normal people, who will break down and lose.
A bit how men can’t understand why women want to talk about feeling so much, psychopaths have a hard time understanding why normal people are so disinclined to be brutally effective. To a psychopath, things are crystal clear. One “benefit” of being analytical, low-empathy and morally utilitarian is that one can arrive at simple and brutal solutions and see them through.
It's funny how consistent this mentality is amongst sociopaths. Everyone comes in different shells, different races, different genders, and sometimes even when I know someone is a sociopath I will just start seeing them as that shell, like I do with everyone else. But they're not like everyone else. They're singular.