It cannot be changed, but…

Sometimes in life you fail to understand at that specific time that you are doing something wrong. A sane mind, under normal circumstances would prefer not doing something, which the brain signals as wrong unless and until the person has some selfish motive.
Things are done without thinking and then the realization strikes , really hard, that it should have not been done. We repent for certain act of ours. That feeling at the back of our mind becomes the reason for our restlessness. We find ourselves thinking about it every now and then, wishing that we could change it.

It hurts more if your intentions are scrutinized because of those actions of yours, creating doubts in the minds of others, sometimes about your character as well.
What is done, is done and cannot be changed. Is it worth thinking about it or the best thing is to let it go and move ahead hoping that time will take care of everything. Is it worth giving explanations or is it better to assume that your intentions, which as per you are pure would come in the eyes of others and they will understand that what happened or what was said was not ill-intended.