simply put, when "shades of grey thinking" was presented to me in therapy, i had a difficult time of rewiring my way of thinking. everything was extreme...i liked you or i didn't like you, i was rigid in my relationships-very conditional thinking, etc. in "shades of grey" i am more forgiving of other's faults and my own. i am able to let go of the controlling behaviors i had/have. i learned i didn't have to be perfect all the time nor expect it of others. i am more willing to live and let live. i got out of the "debating" society in my mind. i learned how to relax. i learned to "play".
hope this gives you some insight to another's perspective.