I used to approach topics by picking the top five-ten books on the subject and reading them. This works, but not as well as I think most people assume. The reality is that you end up not really remembering most of the information you learn. Reading can shape your mind in a way similar to how a river shapes a canyon, but it doesn’t necessarily convert directly to actionable insights.

Instead, I have begun to rely on encyclopedias and spaced repetition, with the idea being that I will actually remember all of the data I’m inputting.

To use an example: I read a popular biography about Rockefeller last year. I can remember the vague outlines of it, but realistically if you asked me to summarize the book, I couldn’t write more than a page. I think most people have a similar experience with reading. Can you name the last ten books you read and write a brief essay about each? Almost certainly not, even if you read a ton.

To combat this, I’ve been adding specific details about Rockefeller to an Anki deck. Things like, “Where was Rockefeller born?” Or “How many companies was Standard Oil split into?” My thesis is that knowing a few hundred facts like this is an order of magnitude more productive than reading a book about the subject. Encyclopedias are thus useful for this purpose, as they present a huge amount of information about a subject in a format amendable for memorizing.