If you invest time and emotional energy into resentment you colour yourself an ugly shade of bitter.
That is not to say that one has to forget the wrongs done to us or how we felt about them, just that to dwell on them is unhealthy. To make them the focus of our thoughts and actions only damages us further.
Soon it becomes that we can’t differentiate the small slights from the outright blatant offences or the facts from the wishes.
Somethings we don’t have the power to change. We have to accept that, no matter how hard or how much it may hurt.