“Ego is the Enemy” by Ryan Holiday is one of my all-time favorite books and I highly recommend it for athletes.
“When we remove ego, we’re left with what is real. What replaces ego is humility, yes—but rock-hard humility and confidence. Whereas ego is artificial, this type of confidence can hold weight. Ego is stolen. Confidence is earned. Ego is self-anointed, its swagger is artifice. One is girding yourself, the other gaslighting. It’s the difference between potent and poisonous.”
Here is a great video summary of the book: