For me, it was never about the sidewalk. I became so involved with that, because I could not understand how a small handful of people got to decide what was best for other people and broke a bunch of laws and bullied to get their way.
So, even now, when people tell me "what's done is done" I tell them - "No, it is not done. It will be done when the people responsible for creating the mess - fix it."
Unfortunately, we can't fix something we do not admit is a mistake. This is true of many situations.
But, what if we approached life as a we approach learning a song -- if we looked upon mistakes as lessons?
The sun rises every day.
May the good in your heart rise to meet the sun, and shine all over the world.