Doing well with money has more to do with behavior than intelligence. Patience, modesty, consistency, and avoiding bad decisions compound more reliably than any single financial insight.
A lot of the book comes back to boring decisions: spend less than you make, leave room for error, do not interrupt compounding unnecessarily, and avoid spending habits that quietly create holes you then have to keep filling. Most of the time, the right financial decision is not impressive. It is sustainable.