The past doesn’t define who we are now or he we might become.
Suffering comes when we attach ourselves to the past and allow it to shape now.
The past is simply a collection of memories in our head. If we do not attach anything to those memories, then we can recount them and the past experiences without pain.
We can’t change it, and why would we want to? Our unique journey has taken us to where we are. It’s over but can be remembered with joy, if accept it and do not shape ourselves from it.