It is a popular fact that nine-tenths of the brain is not used and, like most popular facts, it is wrong. Not even the most stupid Creator would go to the trouble of making the human head carry around several pounds of unnecessary gray goo if its only real purpose was, for example, to serve as a delicacy for certain remote tribesmen in unexplored valleys.
Terry PratchettThe landscape was snow and green ice on broken mountains. These weren't old mountains, worn down by time and weather and full of gentle ski slopes, but young, sulky, adolescent mountains. They held secret ravines and merciless crevices. One yodel out of place would attract, not the jolly echo of a lonely goatherd, but fifty tons of express-delivery snow.
Terry Pratchett