There has always been the saying that people can never truly change. I find this idea to be very inaccurate, and slightly stereotypical. If a boy cheats once, he will cheat again. If a girl hooks up with a stranger, they will forever be seen as a hoe. From a person that has become a better person, I can honestly say that people can become a better person through their experiences or habits. Here is how.
Remember everyone makes mistakes.
Everyone has that one thing they wish they could undo. Since that isn't possible, you need to learn and grow from it. Apologize for the problem and attempt to clear the air with the person/people that were hurt.
Accept your flaws
If you have hurt someone, get a good understanding of where you went wrong, so you know what you need to apologize for. When you have a deeper understanding, your apology will be more sincere. You will also know what to adjust in your personality. Better yourself.
Be confident about your changes.
If you have changed in any way, whether it be becoming healthier or being more honest, show it. Don't let your progress only be shown on a personal level. Let it be know that you have put the effort in to change yourself, your habits. Many people will appreciate your work.
If it won't matter in 5 years, don't worry 5 minutes about it.
All problems throughout your life will not have an impact on you. Sometimes the small things seem bigger than they are. A high school relationship will not matter 3-5 years down the road. Separate what you think will make a difference, and what will not.
Don't let peer comments ruin your progress.
Don't let the words of the crowd destroy you. They truly do not understand your whole story. Keep working on yourself and brush off the comments. No matter what is said, remember change is possible for anyone, even you.
All people have the ability to become whatever they want to be. This goes for occupations, health, and personality. If you have a change you want made in your life, go for it. Put in the effort to make the difference that you see fit for yourself. Life is limitless!