It's humbling to come to class a little more stiff than usual, but invigorating to realize that on those days, I seem to feel the process of inviting the breath into all the tight places more intensely. When the stiffness is there, in the shoulders for example as it was for me today, the stretching of a twist feels keen and sharp, so my mind wanders less. I focus on the breathing more, and the combination brings that unexpected sensation when the shoulder follows the breathing, relaxes, and everything that was held by the tension flows freely again.