Every action you take is a vote for the type of person you wish to become.
No single instance will transform your beliefs, but as the votes build up, so does the evidence of your identity.
This is why habits are crucial. They cast repeated votes for being a type of person.
I picked up the book a while later. It was a great read and I got through it pretty quick! However, the key metric for a book like this is: did it have an impact on my daily life or mental models?