I dated one unhealthy INTJ as well. (Who ended up being diagnosed bipolar, so... I'll try to leave out the stuff that could be blamed by the fact that he was bipolar, not INTJ.) Well, first he was really into himself. Very pseudo intellectual. Used to talk about theology a lot, (had a theology degree) I knew nothing about it. But then he would start saying all this medical information that was completely false. I had to correct him a few times. (Trying to impress a nurse by showing her what you think the blood flow through the heart is... Bad idea.) I slowly found over time that he just bullshitted A LOT. He had a few really geeky but nice friends, who he made fun of a lot, saying, "I'm going to get new friends, I can do better", when one of the friend's later told me that they only hung out with him because he's been around a while and they just tolerated him. He used to say really rude things about people. Make crude comments and claim that no one laughed because it was over their head. He used to be kind of fake, too. His identity was mixed up with his money and the stuff he owned. Not too much substance. He overestimated all his abilities.. (AKA when kayaking once.. "I don't need a life jacket because I'm a good swimmer because I had all this training in the air force blah blah blah." Later, falls off the boat. Almost drowns. Needs me to holler for someone quick to come get him.) Lots of little stories like that. No insight into situations or people. No insight into himself. Needed to be in counseling, had been for ten years, and got nowhere. I think he just went so he could talk about himself.