The book is a guide about how to become a professional poker player. It's basically a self-help book for gamblers. There's not really much about cards. It's more about how to deal with the swings.
He writes about taking a break from a good fame in a bad economy, givng, and how to live life both on and off the table.
I don't play poker much anymore, it was one of the most useful books I've ever read. Many of the concepts also helped me hodl.
The 4 Hour Workweek also helped.