How do you know you're alive. Is it your subtle breathing or perhaps feeling your toes dig into the earth bellow. Or do you believe your mind is a level above all the other life forms. Of course not, no one is so silly to believe that. No one knows if you're alive. Perhaps we are all in a computer simulation taunted and tortured continuously and never ending. Creating our own little pocket universe collapsing under the solar stars of the universe. Crashing amongst each other. How do you know that you are alive? You don't, and you never will.
