Every once in a while, happiness sneaks up on us to do its dirty work. We need to know how to get into our depressed stance so we can stop happiness in its tracks. You would think of depressing moments and walk around as if surrounded by walls. This might seem comical, but it is even more comical that people actually do this without the knowledge that they are in complete control. What we then have are simply stances that generate states.
Every stance is an attitude.
If you want to have a specific feeling, you change your stance. Change your physiology and you change your mental attitude along with it. Thus, we can use stances to determine our states. As we mentioned earlier, when someone is depressed, they change their physiology to match their emotional outlook. The same rule applies when someone is happy and enthusiastic.