Simple as this, when we dance, we feel good. Sometimes when you are in a good spot in life and you hear music come on, you just start to dance. You move, groove, and just start to kind of enjoying it which exasperates more energy within your body which leads you to do it longer. The next thing you notice, you are in a good mood.
Most of the time, when we are in a bad mood it makes it a little difficult to want to go and dance. What Kyle is telling you is no matter what go ahead and dance a little bit, put yourself in that good menu no matter how you are feeling.