As you get older you really get what he is saying, it is wisdom gained through experience. Theory is just that, pretty much what you think will happen, can't replace experience just sometimes helps us go there to get the experience and confirm.
Dont keep making the same mistakes; try to make new mistakes, was it for me - I use it a lot myself because gives that measure of whether peopLe are growing and learning or just 'getting things done and wasting precious time by having to redo it. We do have to challenge to grow and stretch ourselves uncomfortable coversations help and the willingness to engage is a test of character and growth. Every morning I am astonished by the beauty of the rising sun. Knowing how much fun I will have or how much I can learn by dancing in the rain, comes from being an endurance athlete get to do it often, awesome.