Is it just me?

Has anyone other than me felt as though the narc truly brought out the worst in them? That somehow YOU had become the narc? Ever notice that YOUR behavior was becoming more and more like his?

Example: In the beginning I'd go to the local sports bar to meet a gf. I was confident and could go where I wanted to go. If he had a problem with it, it was his problem. However, towards the end of the 2 yr relationship, if he hurt me by making a false accusation, breaking up, and giving me the silent treatment, I'd head to the bar to be with friends (which I KNEW hurt him and triggered his insecurities). So it was no longer confidence that allowed me to go, but rather some type of "revenge" or "lashing back at him".

If it's not just me, can someone tell me why this is?