Sitting alone in the dark is the kindest sort of punishment. There is no one shouting at you and no one waiting for you to explode in response.  You can think, you can dream, you can imagine all sorts of things.

Considering the darkness is total-complete-absolute.  There is no sound, no influence from outside your head.  The clarity that comes from the total absence of stimulation can be enlightening.  How long have I been here?  Are they returning?  When will I see the light of day?  Do I care?

Did the door open?  The light is bright like a thousand-watt bulb shining deeply into my brain.  What am I seeing?  Do I see what is in front of me or what my imagination has created?  I cannot move forward.  What is in the way?  It is the door.  My eyes have created their own light.  Even in total darkness there can be light—from within.