Can you do anything about it?
And if not, will it be a problem tomorrow or one week from now?
What about one month later? Or how about two? Six?
One year from now, will this still be an issue that is worth your attention and emotional labor?
If the answer is no, then mine the lesson to be gained from the mistake or decide on a course of action that will lead to resolving it so you can move forward. Take five to ten minutes to feel the emotions as fully as you can, then let it go.
You might not be able to let go of everything, but it’s worthwhile to examine each issue and consider if it’s truly an issue. It’s more liberating than worrying about every little thing, especially when they’re little.
Because there are more important matters that can benefit from your faculties, your care, and your time. Matters to invest in rather than expend resources on.