What was the name of that rule where you commit yourself to not getting offended?

I've always practiced it, though not always as perfectly as I've wanted (when I do slip up, it's never during an argument though; my stoicism muscle is fully alert at those points in time). An annoying aspect of it is when other people get offended - my emotions are my own problem, why won't they deal with theirs; do I have to play babysitter with their thought process? You can't force someone to become a stoic, but you can probably convince them that their reaction is hurting them and show them that it's desirable for them to ignore offense. To that end, I'm thankful for this post, upvoted.