I have long been skeptical of the educational value of non-fiction books. Mostly when I have bought a book on a topic I found interesting, I either never started reading it, abandoned it after two chapters, or skimmed through the table of contents to find just the things that seemed interesting and ignored everything else. When I did read several chapters in order, I mostly did not remember much later.
There are exceptions, of course. Effective Java is one, which is because it is a compilation of many small independent pieces of wisdom each of which is presented in a compact form. Modern Principles of Economics is another, and that is because it is a proper course textbook for a formal curriculum, with exercises and all.
The classic essay-as-book type of book, however, is mostly worthless to me.
Arnold Kling agrees.