Here's what I know. I know that we all have a heart, air in our lungs and a brain that tells our body what to do before it even happens. What I don't know is why our brains are each built the same but different if that makes sense. What I mean by that is what is different inside ourselves that makes us all individuals? What makes a person a murderer and what makes someone a saint? I know that it has to do our brain chemistry but how is each person's different? Who or what decides that? All my life I've tried to understand why I'm so different. Why my brain chemistry is made up so differently than others. I'm sure that it's a common question for most people whose serotonin levels are abnormal like mine. When God made Adam he was perfect.