We are all people with our flaws and virtues, some of which we are ashamed of, some we are proud of and some we have learned to live with. It is the same with our past, we are ashamed of something and proud of something. If we do not learn how to deal with all this, it can slow us down a lot and often stop us in life on the way to our goals. I read a lot of texts of young people about their thoughts regarding relationships with the opposite sex and I can only give them one piece of advice, then leave all your past where it belongs because if it didn't deserve to be a past it wouldn't even become one.
I think that what is behind of us, should be left behind. There is not anything what we can do to chenge things from our past, and that is why we should not think about that.