Realizing that there are huge differences between giving up and moving on is a huge part of becoming mature in life.
A person with a considerable amount of wisdom is a person that knows when it is time to let something or someone go out of their lives.
Not everyone knows every single answer to every problem, and yes sometimes people make mistakes by leaving a situation too early, or staying in a bad situation for too long, but those who just seem to know the right time for a need in the change of scenery, are those who are willing to listen to their heart.
It is important to think about our decisions in life and to weigh them against our past experiences and so forth, but there are times when we just have to be willing to listen to what is being said in the deepest part of our heart. :)