Use It or Lose It

          Part of a growing mind is the "use it or lose it principle." This compares to a tree. As it grows certain parts get more prominent based on how often they are used. At the same time though, things we don't use get less prominent and eventually unnecessary. This is because even though the brain reaches 95 percent of its full size by the time you are six-years-old, your brain as a teenager grows bigger in different ways. You gain more abilities and a higher range of skills.  Because of this your brain becomes more and more focused but also limited. So work hard at a number of things so that you gain more skills, and lose fewer.