You reminded me of a joke we use in spanish social media:
"I want to be alone, everyone leave facebook"
In these cases, and all the cases where hate or grudges are involved I feel it's better to forgive and don't forget it's the best escenario, because you don't carry in yourself the selfdestruction of hate or the feeling, but you ar conscious of who you are dealing with and his weaknesses. So you go into measuring his reactions to certain things developing a profile if needed. There are cases when you can't just leave the person, like it happens on family matters or at work, so this assesment is eventually useful and a nice cup of wisdom to carry for future cases.
Forgetting doesn't really happen. Forgiving is at best, rare. However, having the memory means being aware of the person and their behavior for future interactions, if there must be future interactions. At some point though, even family get cut off if their behavior is unacceptable often enough.