As I lay on the gurney in the operating room yesterday the anestesiologist put the plastic cup over my nose. I thought I am wide awake. I don't even feel sleepy. When is it going to work. It's not working. Next thing I know the nurse is telling me to wake up that the procedure was a success. We are unconscious of the time when we are unconscious therefore we jump from one state of consciousness to the next. It is only through the confirmation of other people that we know the consciousness that wakes in the morning is housed in the same person that went to bed last night. Other collaborate with our memories so that we know we are remembering reality and not dream. When we dream we are not unconscious but in a different state of consciousness. Only when we awake it may take a few seconds to realize we have changed states but eventually we do yet while asleep we do not consciously know that we are in a different state. If you awakened one day and found you were the only person on Earth what difference would it make which state of consciousness you are in, dreaming or waking since thee is no one else around to confirm the events of the so-called real world?