Songs are written – wars are fought – over a temporary thing called feelings.  Every body has them right?  Yes and no.  Every child is born with the capacity to feel.  Life experiences teach people to turn them off sometimes.  Other people never learn how not to be controlled by them.  One of the symptoms of PTSD is avoiding feelings to a particular event. (http://psychcentral.com/lib/symptoms-and-diagnosis-of-ptsd/000158) I learned when I piled up enough events that I was avoiding feeling I could stop feeling completely.  I felt no sadness, no sorrow, no regret, no shame, no happiness, no joy, no empathy, no feeling meant none of them.  Gray described my existence during this time.