Finished the book and already forgot it? Stop highlighting: how to remember what you read, and the 10 minutes after the last page that decide it

To remember what you read, stop highlighting and rereading: ask yourself a question before you start, close the book at the end of each chapter and say the main idea back in your own words, write in the margins instead of colouring them, and come back to it a few days later. Then, after the last page, do nothing for ten minutes.

You loved that book. Someone asks what it was about, and all that comes out is “it was really good”. You read every page. So where did it go?

Why you forget what you read right after reading it

You forget what you read because reading feels like learning while your brain does very little with it. Three things get in the way, and none of them is a bad memory.

• Your mind leaves the page and your eyes don’t. In a study where people read a novel on a screen, Erik Reichle, Andrew Reineberg and Jonathan Schooler caught readers “zoning out” while their eyes kept moving along the lines, no longer reacting to the words themselves (Reichle, Reineberg and Schooler, 2010). You turn the page; nothing went in.
• Highlighting and rereading feel productive. A review of ten study techniques rated both as low utility, far behind testing yourself and spacing out your sessions (Dunlosky and colleagues, 2013). A page full of yellow looks known. It isn’t.
• Forgetting is the default. Without a second look, most of what you take in fades within days: that’s the forgetting curve, and it applies to books as much as to class notes.

Does speed reading help you remember more?

No. A team of reading scientists led by Keith Rayner reviewed the science behind speed reading apps and courses: there is a trade-off between speed and accuracy, and going much faster than normal costs comprehension. What makes good readers efficient is mostly vocabulary and knowledge of the topic, built by reading a lot (Rayner and colleagues, 2016). If you want to remember more, read a little less, and do more with it.

How to remember everything you read: 5 moves

1. Ask a question before you open it

Before a chapter, write one question you want answered: “why did the empire collapse?”, “what does she suggest instead of willpower?”. Trying to answer before you know helps you learn the answer later, even when your guess is wrong (Richland, Kornell and Kao, 2009).

2. Close the book and say it back

At the end of each chapter, close it and tell yourself, out loud or on paper, the two or three ideas that matter. Then check. That’s active recall, the most reliable study method we have, and it works for a novel as well as a textbook. For a dense chapter, try the blurting method: everything you remember on a blank page, gaps in red.

3. Write in the margins, not in yellow

Replace the highlighter with a pencil. Three words in the margin, in your own phrasing (“so habits beat motivation”), force you to think about the idea; a highlight just marks it. If you can’t say it in your own words, you’ve found the part you didn’t understand: explain it as if to a twelve-year-old, that’s the Feynman technique.

4. Use paper for what matters

A meta-analysis of studies comparing paper and screens found that people understand informational texts better on paper, especially when they’re short on time (Delgado and colleagues, 2018). Your phone is fine for a thriller. For the book you want to keep, print it or buy it.

5. Come back three days later

Spend five minutes going over your margin notes and saying the ideas back, a few days after you finish. A second, spaced session does more than a whole reread on the day. See how to remember things for the full spacing rule.

Where to keep what you read, so it doesn’t vanish

Here’s the catch with note apps: when people expect information to be saved, they remember less of it, and remember instead where it is (Sparrow, Liu and Wegner, 2011). So the order matters. Recall first, then save. Say the three ideas from memory, and only then write them down somewhere you’ll find them.

With MemoryPilot, that takes one sentence when you close the book: “Atomic Habits: make the cue obvious, shrink the habit to two minutes, never miss twice”. Months later, ask “what were the three ideas from Atomic Habits?” and the answer comes back, in your words.

The surprise: the 10 minutes after the last page

What you do right after reading matters more than you think. Michaela Dewar and her colleagues had people listen to two short stories. After one, they played a spot-the-difference game for ten minutes; after the other, they simply sat in a dark, quiet room. The stories followed by rest were remembered better, and the advantage was still there a week later (Dewar and colleagues, 2012).

Now picture what most of us do when we close a book: grab the phone. So try the opposite tonight. Last page, book down, ten minutes of nothing: a cup of tea, a look out the window, your three ideas turning over on their own. It’s the cheapest memory habit there is.