The thought that my covert narc ex would treat the next person better truly haunted me for a while. Especially because I was so good to him and tried my best to meet his unrealistic needs (I've learned my lesson and have no desire to be this way anymore).

My therapist and I had this discussion and the ultimate lesson I learned was that it doesn't matter, that person is now irrelevant to me. Also, what really matters was how he treated you. If you were mistreated by him in all ways that's not acceptable and you deserve better. He wasn't a good person for you and for your life and that fact won't change. So don't worry if they treat the next person better it's unlikely that their being genuine and it doesn't change how they treated you.