Well, as I don't experience most emotions I'll suppose you're the expert here.

What you say about Narcissists has proven true in my experience with Narcissists, sure they feel emotions, but only their own.

Intellectually I can understand "feeling" empathy though I am incapable of such myself. But it is hard for me to grasp how someone can truly know/experience what another is feeling. Like, how is that possible? What does it mean to "feel another's pain"? How does it "work"?

Also, if empathy is simply taking on another person's emotions and feeling them... then how is it really an emotion if you're just feeling someone else's?