“Success is not final, failure is not fatal, it is the courage to continue that counts.” -Winston Churchill
It seems to me that regrets are a part of lived experience. A word said or not said, an action done or not done. A little contrition or deep remorse. They are present and as time moves forward, we cannot go back to that moment again to fix it. While it's not harmful to have experienced regret, it is so to dwell on it.
What are we to do with our regrets? There are a few character-building actions we can take. First, if a relationship was harmed and we have the opportunity, we can seek to make that right, either by asking for or offering forgiveness. Second, we can learn from it. How can we avoid doing again what pricked our conscience? How can we grow from the experience to do better next time? How can we implement our plan to be sure that we are prepared?
It's so important not to waste time beating ourselves down for these things which can cause long term harm as we mentally punish ourselves for our failure to live up to expectations. It takes courage to move past it, but it's what is necessary to grow. Allow it to change you, yes, for the better. Don't allow it to pull at your mind with never-ending sorrow.
In the end, if we are able to learn from our regrets what they have to teach us and then pick up and move on, it gives us enrichment. When we next face a similar circumstance and we are able to apply what we've learned, we will there find joy that has grown up from the soil of our regret.
Do you have regrets that seem to follow you through life, that you wish you could escape? What can you learn from them? Learn those things, and remind yourself that failure is not the end. It's time to pick up and move past those feelings. Put them away and don't give them a foothold in your life anymore.