The brain has 3 parts. The hippocampus the prfrontal cortex and the amygdala. The hippocampus stores your memory from the past if you dont have one you lost a lot of memory. If you are at school it keepd what you learned in class without one you cant remember What you were learning for that test that you had today. Prefrontal cortex makes your dissision`s and it is not going to make good choices till your 18-21. Amyigdala fogs up when you are not happy and it cant think strait till your happy or calm. It lets us think strait.