“Don’t fight a battle if you don’t gain anything by winning.” -Erwin Rommel
Sometimes it isn’t worth fighting.
When your spouse is convinced that something from twenty-five years ago, that has little relevance to today and is essentially meaningless to anything other than their argument and ego, is one way and is the most important thing in the world right now, don’t fight. You can only lose.
As Han told C3P0: let the Wookie win.
Most battles don’t need to be fought.
OK Karen, you can go ahead of me.
Sure, the sky is orange.
Gracefully retreat, maybe fight a deceptive rearguard action so they feel like they are winning.
If it doesn’t matter, it doesn’t matter. Save your ammunition for a strategically important battle, don’t waste it in a meaningless skirmish. Don’t just fight when you can win, but when it is actually worth winning. Pyrrhic victories lose wars, for both nations and relations.