It is a standard consensus that experience is the best teacher. How does just the experience can be the best teacher?
A person can have the same experience multiple times and still doesn’t learn anything. Think about a person who gets into relationship after relationship and just fail every time. What could that person have done differently?
Evaluated experience is the best teacher. Yes, evaluation is painful, so is not changing.
An evaluation may be painful for most of us. The length of the suffering can be reduced significantly if we are ready to evaluate and learn from the experience. Others may cause pain, but we are causing suffering for us. Unfortunately, letting go is not that simple.
What experiences are worth evaluating? How often are we evaluating? What is the basis for the evaluation? All these are decided by us. The power is with us.