Book Summaries - Allen Cheng

I read books to make better decisions and understand how things work. I also forget a lot of what I read.

These book summaries are my way of retaining more information and understanding the books better. I share them online as free tools, and I hope you’ll find them helpful!

About my book summaries

Why are my book summaries so long?

My goal is to capture 90% of the key information of the book in 10% of the text. If I later forget what a book’s about, I can quickly recover most of its content by reading my summary. Thus my summaries usually have between a 10:1 to 20:1 page ratio – a 300-page book will be condensed to 15-30 pages.

Most other summaries I’ve seen capture just 30% of the information in 2% of the text – a 300-page book might be captured in 6 pages. While these shorter summaries do contain the main points, I find them unhelpful for actually changing my behavior. When the summaries are too high-level, they just read like platitudes, not compelling enough to change what you’re doing. No one reads the Ten Commandments and suddenly stops coveting things.

Instead, in my summaries, I reinforce a book’s main points with its key research studies and illustrative anecdotes. I like questioning a book’s objectivity, looking for the cited research papers and countervailing evidence. My summaries also include discussion questions and ways to apply the teachings to your personal situation.

How can it be that a book can be compressed to 10% of the text without losing much of the information?

My summary comprehension works like .zip file compression, in that repeated content is discarded. Instead of rephrasing important points 9 different ways, I state them once; from many supporting examples, I choose only the most compelling few. If the author rambles into unhelpful territory, I discard it.

Necessarily, a lot of information might be lost in the compression. My summary has to omit much of the character and rhetoric of the original books, and most of the author’s original voice. In all cases, if you like a book summary, I encourage you to buy and read the original book. They often contain more personality than my (rather dry) writing. Most writers and readers would probably agree that for high-quality books, there really is no replacement for the original.

How much of the summary is faithful to the book vs. your interpretation?

For the bulk of the summary, I’m faithful to the author and what’s presented in the book. As a reader, you’re probably more interested in what the book is saying and less interested in what I think about the book.

My attitude when reading books is, “what are the best things I can get out of this book?” I don’t obsess over its weaknesses and I don’t dismiss the book wholesale, like some critics do. Even lower-quality books have something to take away.

When I add my own commentary or examples, I enclose them in [brackets]. So any disagreement with things in [brackets] should be directed at me!

Of the dozens of books I've read, these are my all-time favorites. These have materially improved my life in the years since I've read them, and they're relevant to pretty much anyone doing anything. I suggest you check out my summaries below, or the full books on Amazon:

About my book summaries

List of summaries