No matter who you are, you make mistakes. It's just human nature. Many people regret their mistakes in life, but I believe mistakes can only make you stronger as a person. Everyday we make choices and not all the time can they be the "right" one. How can something so horrible possibly become a good thing? Well, it is all about perspective. If you look at a mistake as a negative experience, then you will only receive negative outcomes. However, if you see the mistake as a way to grow and mature, then it will have a positive outcome.
Failure is the biggest fear that humans have, but it is inevitable. Nobody is perfect. Everyone, everywhere, makes choices every day. Sometimes these choices are beneficial while others are destructive. More often than not, people choose the destructive options. This is when a mistake happens. It can hurt those who made the decision or other people, but that's OK. Mistakes happen and once that wrong is corrected, it can be appreciated.
When a mistake is made, do not wish it never happened. Instead, appreciate that it did. Learn from the mistake you made and realize why you made it. The decisions you make in life say a lot about your character. If you can decide why you chose to do something that was not the best choice, then you can decide to make a better one the next time based on previous outcomes. 
Mistakes can teach you more than what not to do next time. They teach you how to be a better and stronger person. If you want to avoid making the same mistake more than once, then you work to make better choices, which means you are becoming a better person. You are stronger because you are able to avoid bad decisions that did not benefit you in past experiences.
Owning up to your mistakes is also a big part of dealing with them. If you pretend what you did was not wrong or try to justify it, you will not grow from that mistake. It is important to realize you made a mistake and fix that wrong with anyone who may have been hurt by it. It is the only way to learn from it.
So next time you make a mistake, do not say "I wish I didn't do that." Instead say "I did that. I'm sorry and next time I will do better." Do not deny you made a mistake. Own up to it. Also, change your outlook on your mistakes. Do not see them as a regret in life. See them as a growing opportunity. Learn from your mistakes so that you can become a better person. It won't only make you stronger, but you'll be a little happier too.
