You have to reach.
Research shows that people who follow strategy B [read ten pages at once, then close the book and write a one page summary] remember 50 percent more material over the long term than people who follow strategy A [read ten pages four times in a row and try to memorize them]. This is because of one of deep practice’s most fundamental rules: Learning is reaching. Passively reading a book—a relatively effortless process, letting the words wash over you like a warm bath—doesn’t put you in the sweet spot. Less reaching equals less learning.
On the other hand, closing the book and writing a summary forces you to figure out the key points (one set of reaches), process and organize those ideas so they make sense (more reaches), and write them on the page (still more reaches, along with repetition). The equation is always the same: More reaching equals more learning.
Update: A better idea by way of Nassim Taleb: “Don't write summary, write bullet points of what comes to mind that you can apply somewhere.”
Still curious? Discover how to practice; an effective way to learn new things and identify holes in your knowledge; and why some people are so much more effective at learning from their mistakes?