You’re only telling parts of the story
You’re telling anyone who will listen what this person did wrong to you. There’s just one issue: you’re not telling the full story. You’re leaving out parts. There might be things you did wrong, too. Ultimately, this person did the worst thing, but you know you played some part in fueling the conflict. When you tell the story of how this person wronged you, you leave out any detail that could incriminate you. You are the picture of kindness, grace, patience, and perfection in the way you recount the story. You almost begin to believe your own version of the story, feeling even more justified in your persisting anger.