It's a familiar expression but details matter. It's not whether the glass is half full or the glass is half empty, it's what's in the glass to begin with! Yes it's a curse word but it's all in good humour as long as it's funny. So are you an optimist or a pessimist? Or a fatalist perhaps? It's a matter of perspective. Are you realistic or mentally ill, sane or crazy? We all need a philosophy of life.