I'm a relatively young millennial a few years into my career. I've always been obsessive about money from a spend-optimization standpoint (and this has been what drives my career, rather than my college education). Unfortunately, growth-optimization is an area where I am sorely lacking, personally and professionally. I started with REI a couple of years ago, but didn't really know what to do with all of the cash that builds up (or doesn't, sometimes) between real-estate purchases.
This book was very insightful for that. Despite its length, it is an easy read thanks to the author's tone. I think it took me around 4 hours to read cover to cover. I also did some ancillary research, armed with the topics presented in the book. I had never really given much thought to emergency funds or asset allocation, because I've never really considered short - medium-term investment options (due exclusively to ignorance on the matter). I figured it would just be cash and real estate. After reading the book, I've identified a flexible number for my emergency fund, and I've found a few investment vehicles that are well-suited to my financial goals.
It's surprising how many people (young and old) unwittingly choose to make bad financial decisions simply because they don't know any better. This book's delineation between "rich" and "wealthy" was appreciated, because part of bad financial decisions seems to be people thinking they can gamble on the stock market (when they're using loaner cars, have huge student loans, and are barely making ends meet) for quick money. This book is for anyone looking for a mature overview of their wealth-building options. If you're looking for a get-rich-quick book written by a glorified sales rep, this isn't for you.