I have read much about forgiveness.  Forgiving others and forgiving ourselves are both important for maintaining inner peace and reducing stress.  What I have found is how difficult that is when you are trying to be better, improve and forgive yourself but are jeered by those who know your mistakes.  It's like Dan Quayle speaking on the importance of good spelling.  Some people just won't let you live down the mistake.  They just won't forgive you.  It's at these times we have to consciously remind ourselves that the failing is theirs, not ours.  If you have acknowledge the mistake, taken responsibility for it, tried to make amends when possible and work to not make the same mistake again, then you can forgive yourself and ignore jeers of those trying to bring you down.  Always easier said than done.  It's a process and one that takes work. Just don't give up and decide they are right or that you might as well just be what they think you are.