To represent the act of being human and alive.
This prolonged concentration always makes me feel like I have come out of a very long sleep in which I dream of muscles and joints and skin. Then I wake up, get out on the street, and everyone is suddenly naked.
Lines are more discernible and colours are clearer.
It is one of the few times that one is conscious of another more than oneself.
This lack of self-consciousness lingers for minutes, sometimes hours, afterwards. It is exhilarating.