This is true in relationships and also pertains to moving, having to say goodbye to family and friends, making a career change, saying goodbye to old habits/lifestyles,etc. Be Brave enough to say goodbye and life will reward you with a new hello :)
Life becomes easier when you learn to accept an apology you never got - Robert Brault some people need to learn morals and manners. When you're wrong you're wrong accept it and do something about it. If not it doesn't matter life goes on.