Humans should learn to forget about it and let it go. Dwelling on the past makes your life miserable. Not only you are suffering, people around you and also those who were also affected by the same incident will also be very miserable. I am not saying that we should all be soulless humans and have no emotions at all. But sometimes, we have to understand that in different positions, we have to act and speak differently from the rest. If we act no differently from them, who can they to rely on the next time something similar happens? Or even worse? 

Maybe I am wrong but just my point of view.