If all time exist here and now

So this means nothing is past and nothing is future only NOW

Which means a past moment still exist

Which makes it clear that you can go back to a past moment! With your mind and imagination you can change something!
So if there’s a past moment or experience that bothers you, you want to change it or take a different decision about it.. Then close your eyes breath go live in that moment and make a change in your mind!
Open your eye your done