Today's exercise has to do with forgiveness. Or a lack of it.
Make a list of transgressions, or things that can start long-standing arguments. No such thing as too big or too small. Think Dave vs. Oprah (nobody even remembers how it got started), Hatfields vs. McCoys, Great Taste vs. Less Filling.
Explore the incident and the idea of forgiving what happened. Compare and contrast, use examples, offer yourself or the person offended alternatives. Find a way to empathize with the offender. Not necessarily forgive or side with them, but find out what put them in that place.
Look at Dean Young's Poem Without Forgiveness at Paris Review. (The poem's complete. The reference to the "rest of the poem" behind the paywall is for the rest of the "Five Poems by Dean Young.")