Experience is the best teacher so I have been told. I think that is probably correct but there is an old proverb that adds an appropriate and accurate caveat: "but the tuition is high."
Experience is not always the kindest of teachers, but it can be argued that it is surely the best. Archibald MacLeish suggests that the "only one thing more painful than learning from experience is not learning from experience."
Experience is the only source of knowledge according to Albert Einstein. That includes the pleasant as well as the uncomfortable moments of life. There is something to learn from every effort or decision. Sometimes we get it "right" and sometimes we don't but every occasion provides opportunity to learn.
When we "succeed" there is always something to learn about why that effort went well or what led to the good decision. Reflection on times that we accomplish what we intended or met the goal that we set can be beneficial for the future.
Many people conclude that we learn more from our failures than our successes. That could be because we seem to fail more than excel. Whatever the reason it is important to learn from our mistakes.
There is real value in making mistakes because you can learn a better way that leads to success. That is not to say we should be given a license to make mistakes. But the freedom to try your best and be OK when you make mistakes is a wonderful way to learn- if you understand that committing mistakes is alright, repeating them is not.
Whether we learn from our mistakes or not is largely determined by our attitude. If we refuse to acknowledge errors in judgment or inaccurate assessments, we are destined to repeat them.
The "if only" complex will also prevent you from learning and moving on. If only I had done this. If only I had not done that. If you hold onto the painful experience and beat yourself up by repeatedly looking backwards at the mistake, you will never overcome the sense of failure and regret. "If only" holds on to the past and therefore cannot move into the future. Getting over a painful experience is much like crossing monkey bars. You have to let go at some point in order to move forward.
A very different approach is the "next time" attitude. Don't ignore or deny the mistake. Instead reflect on what was done wrong or what was not done and ask what could be a better way next time. This will most likely prevent you from making that same mistake again, or often. Soren Kierkegaard said that "life can only be understood backwards; but it must be lived forwards".
The Apostle Paul learned from his mistakes but was not bound by them. He realized that he was not perfect and he understood the need to "forget about the things behind and reach out for the things ahead." He knew that God would help him to overcome the past mistakes and would provide opportunities for new beginnings. Consequently he pressed on to reach the goal that God had for him.
Life provides ongoing opportunities to learn and grow. Our experiences can teach us a better way so that we can become the persons God created us to be.