Or so people spend five years in a relationship and learn nothing. On the other hand, there are people who may engage in a short-term relationship and cause a world of lessons to take away from it.

If you are in the state of mind in which you experience anger or resentment against an ex, then you are not ready to begin a new relationship. It is only when you are prepared to forgive and let pass away that you will be unrestrained from the emotional ties to your past relation and be ready to make your heart and mind to someone else.