Experience is also the key to your success. Because it is something that no school teaches. Many theories but not practice to learn experience is meaningless.
I am sure that with experience, we can learn many things and we can grow step by step from our experience. besides that, if we have many experiences in our life, we can make a good decision and we can solve every problem that might be we face in the future. as long as we can learn and not forget what we get from our experience, we can increase our quality and we can survive. I think we still need theories to learn something new that we don't know so we can do some practice.