In a relationship why do people always want to open the ex-files?

In a relationship do we have to go backwards to go forwards?, because it seems that we want to know about the past and it seems that we can't go forward without knowing what we have in the past it's like having a wound that won't heal and sometimes we go overboard in wanting to know what our partners did in the past and in a way it starts to ruin the relationship because people have this hole that needs to be filled but what if your past brings up memories which should be left were they were buried so it causes more problems than it solves. Are we that curious that we have to compare ourselves with everyone else they have had?

But it still doesn't answer the question why do people bring up the past, Is because we all feel insecure about what that person has done before and whether they have seen and done better so there is always this doubt in your mind, this little voice asking you have you done the right thing?

But is this the only reason????? Can people really want to know what went on in their partners past??? Do we all want a sense of control about what went on????

After asking Julian and Sarah-Lee from The George, Julian said he would open them up so he could get a sexual rise out of his partner, which would lead to an arguement, and 9/10 times it would also lead to make-up sex and use what he know to help him, give his partner what they wanted.

There are so many questions on the reasons why people are hell bent on knowing the past but in trying so hard to see the past do we see forget to look ahead of us?

Some people say that this baggage can help in early conversations about what we talk about in relationships as we use are ex’s to say what we want in the future, however do we know when to stop, or do people know when to stop asking and digging?

But even with all these questions will we ever know when to open and close are ex-files?