You spent your early years developing some neural networks while allowing others to atrophy. Some of your neurons got swept away like autumn leaves, and that streamlined your thought process. You added new knowledge, of course, but you did that in areas where your electricity already flowed. If you were born into a hunting tribe, for example, you easily added more useful hunting information, and if you were born into a farming tribe, you had solid farming circuits to build onto. You ended up with a brain honed to survive in the world you actually lived in.
