There is an old Patty Griffin song - Long Ride Home.
My favorite lines in that song are
"Forty years go by with someone laying in your bedHow hard would it be to just be a bit kinder. I hope I choose kindness as often as I can. When things are difficult or I am frustrated and I am angry or hurt and just don't want to be kind, I ask myself how hard would it really be to be kind. I also ask myself if sometime I may regret not being kind in that moment.
Forty years of things you say you wish you'd never said
How hard would it have been to say some kinder words instead"
Usually being kind costs nothing and is so easy to do.