My mom told me a good anecdote that helps with patience: a person on the road is driving like an asshole, cuts you off. You get them to pull over and go up to give them a piece of your mind when you see a baby in the back screaming its head off and you can clearly see the parent is tired and out of patience. The parent couldn't take it out on the baby and didn't have time to pull over, so took their frustration out on the road.

I always ask myself "what's an understandable reason for that person's behavior?"