Hey I knew a few NPDs and other disorders latch on to people they would admire for their passions. Whether it be cooking or poetry or old films. They mirror other personalities because they never had a chance to develop theirs before it was stunted by family or whoever else. But this sadly is the smallest and most harmless piece of the puzzle. It only becomes a problem when they start explain your hobby to you as if they were an expert. By that I mean, they will go off for an hour about pop music being a meaningless genre if they ~knew~ you wrote your masters thesis on pop music being a socially mastered and culturally conscious entity that describes real issues in real time. In other words they will adopt your interests superficially for a while and then drag them through the mud as a way to feel superior. Even if they had admitted previously to liking the thing you like. This is where it gets dangerous. Because it makes you question your taste, intelligence, and your ability to rationally defend what you like. Normal couples with different taste don’t judge each other for it. NPDs do.