"I was aware that we were both silently making those inevitab..." — Emily Giffin quote meaning

I was aware that we were both silently making those inevitable comparisons, putting our relationship in context. She is more this and less that. He is better or worse in these ways. It is human nature to do this--unless its your first relationship, which might be the very reason that your first relationship feels special and remains forever sacred. But the older you get, the more cynical you become, and the more complicated and convoluted the exercise is. You begin to realize that nothing is perfect, that there are trade-offs and sacrifices. The worst is when someone in your past trumps the person in the present, and you think to yourself: if I'd known this, then maybe I wouldn't have let him go.