“If a joke doesn’t work — fix it or dump it.”
See your mistakes, acknowledge your mistakes & fix your mistakes. Oh, and don’t repeat your mistakes — at least not in the same way.
You have to be able to tell when something’s not working, for whatever reason. Part of it is the need to step back and evaluate the situation with an objective eye, and part of it is the strength to say “This is broken and I either need to get help to fi x it or I need to say ‘enough is enough’ and walk away.” This is ESPECIALLY important in relationships, personal and professional alike.
Know when to throw in the towel and when to just toss it in the wash.