My bookcase has 27 books with insights on the mental game of baseball. Those books are the best of the best; others were given to Goodwill. Mind Gym will increase my number to 28; it’s worth reading!
One lesson is know your numbers, which was about the athlete being aware of his body and its’ characteristics when performance is optimal. Applying that to myself, I am aware of how I feel when my desire to write is on fire, like it is now.
The book encourages the reader to ask countless questions about themselves. Asking questions is a big part of improving, both for players and for managers/coaches.