At what point in a new and current relationship did you find closure with a relationship/person from your past? Can you really have closure with someone whom you were truly in love with?

Aside from my past issues, a girlfriend who has been married now for over 20 years ran into a former boyfriend, the one just prior to her marriage. She said they were able to just sit and talk about the past, the current stuff, just everything, wellllllllll, despite the fact that I have seen her with her husband and never thought in a million years she would cheat on him, she did!

She claimed that there was obviously never closure, despite the length of marriage and their time apart, she never resolved her feelings for him, the other guy.

So hence the question, can you really have closure and how do you know when you've really closed that chapter and have moved on?