It has been said that life is the most patient teacher.
You will be presented with the same experience over and over until you learn the best way to deal with the situation.
This is not because life is cruel. Rather, it is because things have a way of coming back to haunt us when we don't deal with them.
One form of intelligence is the ability to learn from mistakes.
When you are presented with a painful experience, take the time to think about how you can avoid it in the future.
This is an example of a lesson learned.