putting my two cents in because i have NPD AND low empathy. cognitive empathy exists. we can understand, rationally, what a person is going through, even if we don't full feel it. ("that's common sense, i fear" /ref)

also i have never (in my experience) met a narc who would publicly admit to their disinterest/lack of caring. the whole point is for you to trust me, why would i say something that would make me seem awful if it doesn't serve me?