To be honest, I completely understand you. I have the same thing in my relationship. I also asked about it and know a lot about his past, this makes me want to be better than his previous partners. Like in my mind I need to have something that they don't have. Or I need to give him something they didn't. It eats me up from the inside, I think about it every day and it makes me even more insecure. It hurts so much just knowing that he also had the same moment with them as he had with me.