Narcissism Accusation

An employee at my gym jumped into the elevator as the doors were closing and they popped back open. (Yes, my gym has an elevator. And I use it, but only to go from the 9th floor to the first.) It's a slow elevator, and I never hesitate to stick my arm in the closing door to get it to open back up. I never thought about it too much, but I suppose it's something of an inconvenience for everyone already in the elevator. This guy who dove into the elevator joined me and a woman. The lady tore into him with something about how he was slowing the rest of us down (She meant me, as I was the only other person in it.). She called him a narcissist and said, and I'm not exaggerating, "Aww, mommy didn't love you enough?" Then she said, "You put the 'n' in narcissism." And I thought, what does that even mean? So I said out loud, "What does that even mean?" (Like I said, it's a slow elevator.) She turned to focus her glare on me instead, and at that moment the elevator shuddered to a halt, but the doors did not open. I thought, please don't let me get stuck in the elevator with this woman. So I said, "Are we stuck?" After a few moments the doors opened, and thank god. It would have been like a steel cage death match in there.