I guess i should be careful how I title this one, this is not meant to be used in bad terms. This is something that you say in order to tell someone not to be angry when someone has upset them. Anger can be exhausting and embarrassing at times.
Be with someone who won't stay mad at you, who can't stand not talking to you, and who's afraid of losing you. Don't let your anger take the shape of fists. Don't go to bed mad. Life is too short. Keep it simple.