If a person wants to be a part of your life, they will make an obvious effort to do so. Think twice before reserving a space in your heart for people who do not make an effort to stay. Must remember this!
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 :)