There are occasions that all of us played a part in the blame for something. Our part in the blaming event has become hidden in forgetting what we did with whom. We cannot recall the events or actions of the time. Or maybe we have gone into denial of what was actually done.
It is helpful to be aware that an error in judgment or misunderstanding is more about choosing the wrong option at the time. As soon as you realize this it is your opportunity to change direction. Perhaps you are partly to blame. If so, admit it. At that moment you make the choice not to repeat the same mistake again.
If you make the choice not to repeat the same mistake and slip up, take heart and keep trying. You will succeed.