We can't possibly know everything about people we are just meeting, or that we interact with in a limited context, so it's probably our best bet to be kind and compassionate, no matter what. Being righteous, we sometimes feel entitled to straighten someone out, to snap them into reality (our reality), or to call them out for wrongful acts, but maybe it's not our place to do this. Maybe it's rarely, if ever, our place to do this.
As human beings, we are sensitive and fragile and easily tipped one way or another. We personalize hurtful comments and take ownership of other peoples' poor opinion of us... or maybe their over-inflated opinion of us, depending. As such, we might all do better to keep our opinions to ourselves, because the truth is, not having all the information, our opinions are likely to be wrong, and we could do damage without knowing it, to someone's reputation, or blood-pressure, or their state-of-mind.
Let's leave judgment, aggression, and our desire to punish alone. Let's leave these things up to fate, where they belong. We all get what's coming to us in the end. Let's spread kindness and compassion and look for the best in others. And if we feel wronged and attacked, let's try for forgiveness and understanding instead of vengeance and retribution. We think we know it all but we don't. It's not up to us to straighten anyone else out or make them feel small. What's up to us, what's our rightful responsibility in all of our interactions, is to simply do no harm.
Even if I feel angry at someone, and attacked, I accept that I may not have all the information, and choose forgiveness and kindness over defensive hostility. I feel better about myself when I am kind.