I certainly agree on avoiding doing *nothing* and the comparison of the brain to a muscle. Like a muscle, the brain needs to be challenged to grow and develop. But also like a muscle, it also needs time to recover. While we can't rest our brain like we can our muscles, I find that having a day where my brain is mostly consuming (ie. books/TV, with friends, etc) rather than exerting (ie. work, learning, creating) allows me to refresh and prepare for another week of exertion.