If you can’t name three things you won’t compromise on, somebody else will pick them for you.

Lines you have never put into words are easy to cross by accident. In the moment there is always a reason, the group is going that way, it is just this once, and without something decided in advance you negotiate from scratch every time. People with clear limits are not more disciplined. They just did the deciding earlier, when nothing was at stake.

Write three down today, in specific language rather than values. Not honesty, but I do not cover for people who are lying to someone I know. Keep it short enough to remember at a party, because that is where you will need it.