Answer:
I have experienced massive amounts of regret, in just my short period of living. I think there are many methods to moving past regret, for sure. One way you can do this, is to ask yourself if remembering what you did, is impacting you, or someone else in the present. If so, then maybe possible action is in check. I mean this by, someone may be in need of an apology. Another way you can shake past this is to remember, that you were not the only person who messed up that day. Someone else made the exact same mistake, and someone other, had an even larger fault, than yourself. Sometimes the only thing keeping you from healing, is yourself, and you have to forgive yourself for your action, and keep going.