Half maybe, but not less. I’ve read a lot of book abstracts (from getabstract.com) of business or pop science books in about 6 to 20 pages. They really do seem

Half maybe, but not less. I’ve read a lot of book abstracts (from getabstract.com) of business or pop science books in about 6 to 20 pages. They really do seem to contain all the pertinent points, but in my experience you read them, nod your head (“that makes sense”), and then the next day have forgotten all about it. Zero retention. A book, by contrast, is much longer and, yes, repetitive, but also gives context, examples, applications, anecdotes, etc., and in my experience all this seemingly superfluous stuff helps with retention.