Joshua Foer in his new bestseller, Moonwalking with Einstein: The Art and Science of Remembering Everything (Penguin, 2011) writes, “I don’t think I’m an exceptionally bad reader. I suspect that many people, maybe even most, are like me. We read and read and read, and we forget and forget and forget” (148). Yes, that sounds like the testimony of an average reader, myself included. However, he writes:
When the point of reading is remembering, you approach a text very differently than most of us do today. Now we put a premium on reading quickly and widely, and that breeds a kind of superficiality in our reading, and in what we seek to get out of books. You cant read a page a minute, the rate at which you are probably reading this book, and expect to remember what you’ve read for any considerable length of time. If something is going to be made memorable, it has to be dwelled upon, repeatedly. (147)
Yes, reading requires reflection. But I’m not convinced this proves the danger of reading quickly and broadly, at least not with non-fiction books. In fact I encourage readers to read various types of books at many different reading speeds—including very quick speeds. When it comes to retention I think the bigger problem is that a typical book reader has a hard time isolating the critical selections of a book. The fact remains that we remember only about 1% of what we read, a lesson from the life of a relatively slow reader, John Piper.
See I think the reason we forget what we read is not because we read too fast but is because, as Foer writes, “Few of us make any serious effort to remember what we read” (148). In my forthcoming book I explain how I attempt to remember what I read by locating the most important points within a book (which requires that you determine why you are reading a particular book in the first place). Then I mark those sections as I read with marginal notes and then return and invest a disproportionate amount of time dwelling on the particular isolated points, repeatedly. In this way I continue to read quickly and yet I also develop my focus and increase my retention. I cannot remember 99% of what I read, so I don’t try.
Okay, so how exactly do you isolate a concept in a book? I guess I just did.
Tony Reinke 
Someone once compared reading to like eating. You may not remember what you ate for dinner a few days back, but your body was nourished by it.
I think the analogy applies for listening to sermons and reading books. We often are nourished and grow from the experience even if we don’t remember specifics of what was said or what was read.
I wish I had a better memory, so that I could remember more of what I read. Yes, CJ Mahaney and Piper are glad to remember 1%, but won’t it be better to forget 1% and remember 99%? Oh, the day when brain science is well developed, and oh the day when brain enhancement is as accessible as upgrading your computer.
8-(