Absolutely weird about the agelessness. The first website I started reading about N's said they don't seem to age. My mom is now 77. At 70 she looked 50. She has had very minimal health problems. And she didn't go grey until about 60 or so either. The theory on this site suggests that a possible reason for this is they have not really LIVED their lifetime. They have spent a lifetime in la-la land so to speak. I believe this, my mom actually told me when she about 70 that she still felt like a kid inside. I didn't realize it at the time, but that statement speaks volumes now.
"Without me, you're going to fail!" Sounds like a statement my N husband likes to tell my kids a lot. And if they don't respond correctly he withdraws completely in a pout mode. "After all I have done for you!" or "Fine, then I just won't help at ALL!" Hot or cold. Black or white. It is indeed frustrating to watch, I can only imagine how it feels. You are way ahead of the game if you have figured it out at what sounds like a younger age than most. Just keep reading or posting, you will figure him out and feel lots better.
My parents??? "Oh, who are you? You're still here?? What was your name again??" ETC!! As long as I behaved they left me alone. VERY alone.
Have a good one!