There is a good MOOC on coursera on the topic of learning and creative working: Learning How To Learn by Barbara Oakley (there is also a book).

She talks about focused and diffused mode of thinking. The main idea is that to create new neuron connections (memory or understanding) you've to work hard on a topic - the focused mode - and then take a break - the diffused mode.

By switching modes you help your brain. Of course, you can't just go do something else without working hard first ... :)