When you love someone. truly love them friend or lover, you lay your heart open to them. You give them a part of yourself.that you they can hurt. with a map of where to cut you deepest and most painfully on your heart and soul.
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 :)