As the resident malignant narcissist of PC I will confirm this as correct even if a bit simplistic.

For me it's not just that I'm not sorry. It's also that I don't see whatever I did as a big deal/at all serious/wrong. I see it as normal.

Here's the thing about that: if I acknowledge the things I've done as being gravely and seriously wrong, then that would force me to look at things that have been done to me as gravely and seriously wrong and frankly I cannot tolerate that.

So I minimize what I do to others into it not mattering at all because I have to see things that have been done to me as not mattering at all/having zero effect on me because if those things actually affected me then that totally shatters my sense of self.

In other words: as per usual, it's not about you, it's about me of course!

As for why the unusual amount of insight: I've been in therapy for NPD for a long time now.