Not a TAAT but inspired by one.
A mil makes a comment that upsets a DiL does the DiL hold on and remember or move on? If a DH makes a stupid comment should it be brought up years later? Your sister says something that stings.
My mum holds on to grudges, I know things my aunts did when my mum (who is 85) was 20. She has spoken at length how my DGM didn’t do things or did do things, my mum was obviously young and vulnerable at the time, but I don’t feel I needed to know about these incidents.
When my mum discusses and pulls apart past events none of this seems to make her happy, she is clinging on to the hurt and offence and reliving it, being offended anew. When I had a mil of my own my mum jumped to put her experiences on me and attempted to make me feel her offence and added mine to it. She now reminds me of things that happened 30 years ago that I have long since forgotten. She did the same thing with dad and her own sister.
Now if someone shows you who they are believe them. I’m not talking about abusive comments just the kind of stupid things you might say in a family situation. Don’t continue in an abusive relationship. Don’t allow yourself to be a perpetual victim. You need boundaries to be safe. Sometimes people make mistakes and emotions can run high. But, but, but in a normal family relationship, over decades with give and take you have to let some things go to be happy.
AIBU to suggest sometimes remembering and holding grudges just makes you miserable.