According to the New York Times, "toddlers are not the only ones who do better after an afternoon nap." Research has shown that adults who take a ninety minute nap after lunch raised their learning power. Their memory primed in order for them to retain more information. Apparently, naps do restore your ability to learn. Your brain is a sponge that soaks up more information when it is well rested.
I take a nap practically every single day. An hour nap, or so, gives me the energy boost and motivation to get things done. I can agree with this article. It puts enough logic together to actually make sense. Maybe this is why I do better in my afternoon classes then morning classes. I napped in the beginning to prepare my brain.