Reading and retaining information is the key to knowledge. One of the keys of personal development is reading and not only reading but ingesting in your mind what you read. This article notes a recent study and explains the best way to retain information and place it in your long term memory:

If you’re like many professors, you’ll tell them something like this: Read carefully. Write down unfamiliar terms and look up their meanings. Make an outline. Reread each chapter.

That’s not terrible advice. But some scientists would say that you’ve left out the most important step: Put the book aside and hide your notes. Then recall everything you can. Write it down, or, if you’re uninhibited, say it out loud.