Trying to be a good person is all we can do @Bunniekins When you do things you are not proud of when you are unwell there are exenuating circumstances - you are not always in control of your actions and that makes it so much harder to reconcile the well you with the unwell you. Our whole brain chemistry can change when we are unwell and for some illnesses that can entirely change your behaviour - that is not something you can control.
There are some things I find it extremely hard to forgive personally no matter the circumstances and other things that can certainly colour my view of people. You are very right though that we all no doubt have things in our lives we are not proud of and it shows the character of a person to have guilt and regrets over those things. Just feeling those things shows your remorse and desire to be better. For me it is totally the degrees to which you are hurt - are those things that have been done unintentionally or are they intentional acts to cause the most pain - and within that again are there extenuating circumstances such as illness, mental impairment or defending oneself from harm (to name a few). In the end every situation, every example, every action/behaviour is different for every individual and we often do not know the bigger picture.
Then again I have no empathy or time for anyone that hurts children or animals. I also found it very hard to reconcile the person I knew with someone that had previously assaulted a women. I knew the precipitating factors and also believed the damage caused was accidental but the fact that he lashed out at all with all the training he had had made it hard to get around. It certainly did taint my view of him and having a DV background and knowing how I felt being on the receiving end certainly added to those feelings.
Experience, our past, our values and beliefs and the view we have of the world in general all add to what we believe and what we will tolerate - and yes also what we will forgive and move on from. I also think we here are our own worst critics but that also equipts us with the empathy and understanding of others to weigh up all situations with our own values and beliefs.
In my very long-winded way I am also saying that no one is perfect and all we really have is ourselves, our values, our beliefs, our tolerances and our knowledge ...and in the words of Skakespeare "This above all to thine own self be true ...and it must follow as the night, the day ...thou canst then be false to any man".