Everyone has a past. No one lives in it. Everyone has done some stupid things, it's done, it's over. Everyone has a history. A HISTORY. What happens today will not be history until tomorrow. You cannot redo history, it's done, it's over... time to move on! Everyone learns from things that may have happened, people grow and move on. You shouldn't have to spend your life being punished for things that happened then. This is now. You are living for the future, for the moment, for the present.
(P.S. when I say "you shouldn't have to spend your life being punished..." I clearly do not mean criminal acts and you're in jail for murder or something, now that... that my friend is worth punishment!)