Meditation is such an important tool these days because of the vast amounts of information being tossed at us. The mind can go on excessive journeys of calculation when the most obvious aspects of our human lives is right in front us.
I often tell classes when I have them in a rest period, to drop all tension from the previous exercise. What happens after a tough pose or movement is that the mind wants to stay ready so the student keeps the body tense in anticipation of another tough exercise. When you're done with something, an action, a job, an exercise, then you should drop everything associated with it and become neutral. There's a time for action and a time for rest. The applies to everything in life. The mind is, in part infinite and we often carry around much more than we need anticipating the next tough thing in our lives.