We all face struggles in life, and it's likely that when we face those struggles we'll deal well with much of the struggle, but still have some regrets since it's difficult to deal with every struggle with total success. For example I met with a confusing, troubling struggle recently. Honestly, I didn't know exactly what to do, but I did the best I could by seeking expert advice, reading about the situation, and consulting my values. The situation was never completely resolved, and I had to accept that. I also have to accept the fact that when others deal with struggles, they won't completely resolve those struggles--people are not perfect and neither is life.
Since imperfection is part of life, once we do our best, we have to put those struggles aside and move on. If greater wisdom or solutions arrive later on, we can revisit struggles to make change, but in the meantime, it's best to file those struggles away and move on to better days. Onward.