My thinking on this is that we all can decide in what state do we want to be. Sometimes we want to be in a sad state to let our emotions all out (like when somebody dies), but other days if nothing bad has happened why would I want to choose that state rather than gratefulness, joy, happy states. Motion creates emotion is quote from Tony Robbins and it can be viewed metaphorically. For example: trying to be sad while putting your head up in the air. It is just not possible because certain body expression and stance triggers certain emotion and that is what we can use to change our state if we want!