DON’T burn bridges
This is an addition to not being ignorant as the “I don’t need you” mentality can come around to bite you in the butt. Always strive to end things on a good note as you never know who you will encounter down the road. What if you put your former boss in his or her place now and have to do business with them in the future? Or perhaps your boss is already acquainted with your future supervisors without your knowledge? Maybe that co-worker you cussed out will become your boss down the road. You never know how life plays out so do yourself a favor and keep calm when you move on.