I guess we all would have liked to do things a bit differently ...perhaps have a delete button for certain portions of our lives.

Yet, isn't that the beauty behind being open and honest about it??

If we make a mistake, we can share with others our understanding of what that mistake was ...and perhaps spare them from making the same mistake.

Of course, that is dependent upon the fact of whether we know what the mistake is.  All of us make mistakes that we may not realize are mistakes.

Also, if we feel the mistake has potentially hurt someone ...we can go to that person, admit that we are not happy with the way things went, and then work to reconcile or remedy the situation. Seeking forgiveness is very powerful, and is often much appreciated.  

Many mature individuals will dismiss the offence, and say, "Think no more of what has happened  ...forget it!"  

And they feel the hardship was worth the now renewed understanding, and they may even feel their friendship is even stronger now as a result of the difficulty.