How to Let Go of Negative Experiences

I would never voluntarily go back to school and take writing English classes. I want to learn how to use bigger words, because I know a lot of big words. And I also want to take a psychology class,. Since I talk so much about mental health and how the brain works, I want to be more of a professional on the topic. Let's do... Okay, letting go of negative experiences. Simply you can't change the past. You will not gain things from it, except that it happened. All you can do is work towards being a better person. If you keep focusing on how you were a bad person, or what you did that hurt someone, you won't change.