If we seem narcissistic, we're compensating for the fact that oftentimes, we truly don't know who loves us in this world.
Why does it mean that? Yes, when an ENTP is messing around, their tongue and cheek humor may sail right over the majority - but I'm not referring to humor. If asked a sincere question, I don't see them ever keeping quiet

ENTP's
love talking. And as they're rather narcassistic, all their talking is usually about themselves. I don't see your type keeping hidden.
Sometimes displays of ego are intended to create a false internal reality. ENTP's over-intellectualize things to protect themselves from simple truths.
I'm a female ENTP, and I can't relate to that at all. IRL, I am actually the listener more than the talker, in one on one situations, with friends or other loved ones. I'm acutely aware of cues from the others, that they're getting bored, or humouring me, or they have no interest in the subject matter, so, I'll abort going deeper or sharing more. While, it seems, that the other doesn't afford me the same courtesy to be aware that I really don't care that much, because I'll continue to listen and question and respond, to their minute details they share. Because I vibe that they need to get it off their chest.
I actually don't like talking much about myself, unless asked a direct question, asking me to expand. Some of my closest friends don't even know about certain hobbies, passions of mine - because it just never came up, and I don't see the point of sharing, just because.
Only one other person do I take on the active "talker" mode with, my ENFJ best friend. Even with my INTJ ex, I was more the listener than him. While in the outside world, he'd be much more quiet.
As for the narcissistic tendencies, again, I can't relate. I can seemingly come off that way, but, it's all sarcasm and joke, and it's actually really masked self-deprecation, and, I'm "testing" to see if the other falls for such illusions, the smoke and mirrors pitch, or if they smile at it, yet, choose to dig deeper.
When I do something ridiculous and it somehow worked out, I'd often say to my INTJ ex, "I'm fucking awesome!".......I'm actually taking the piss out of myself at that moment, because I also realize how ridiculous it was, and the giddiness of it working out, regardless of the hair-brainedness of it all.
So, when another time, while we were driving on the highway, the INTJ points out to me, this crazy-looking dude, driving his beat-up old, rusted, hatchback car, with garbage bags piled high at the back of his car, with :546: old headphones on, and a walkman, headbanging away, seemingly oblivious to the world, how he appears....and the INTJ says, "Look, he's awesome, just like you!"
That's what counts, because the INTJ got it, and I can only smile, and say, "Exactly!"
If you take me seriously at that point, and think I actually believe such bloated statements, I'm going to lose a bit of my closeness with you (respect for?), because you are not trying to see me, just the show I'm putting on for you. I.e., you really just want to be entertained by me.
There's a truth I'm hinting at, with my seemingly grandoise "narcissistic" statements, and it's not the obvious interpretation.
So, maybe, that's ^ what OMT's quote was getting at?
We all walk around, and cater our presentation of self, situationally, and, it's understandable, but, funny to me, at the same time. I often see the masses as clowns who don't know that we're clowns. Thus, I push those limits, in regards to myself, often. To see who picks up on it, or who gets sold the lines.