Psychologists have found that brief resting periods after learning aids memory. In studies, when people take a little rest after learning, say, a string of numbers, they do better in recall than other people who’ve been given another task straight away.
It is thought that this little rest helps consolidate the memory, making it easier to retrieve. On the other hand if you go straight on to another task, the memory doesn’t have a chance to solidify.
[E]ven after 7 days people’s memory was enhanced when they took a 10-minute break after reading the story. In fact, 7 days later people who’d taken a break were as good as those trying to recall the story just 15-30 minutes later, but without the break.
So perhaps this helps explain why I have a clearer memory of books I’ve read on trains.
It also shows that one of the pleasures of reading—pausing to let it wash over you—is not only agreeable but also helps you remember what you’ve read.