““The prefrontal cortex is a complex, fragile region of the brain. In its healthy state, it directs human impulses toward rational choices and away from destructive or self destructive behavior. It allows us to deal with the present moment while storing plans for the future. Yet as the newest part of the brain to develop in human evolution, the prefrontal cortex is also the region that takes the longest time to reach maturity, or maximum operating efficiency. It will not be fully functional until the person is past the age of twenty.””