I was at a class this week. The sensei was discussing a particular set of moves related to pressure points. He demonstrated it to the class with flawless, fluid motion. We practiced it a bit. I noticed that once you did the technique correctly, you became happy. I think that happiness is something that when practiced... becomes as reflexed a reaction as that shown by the sensei. It's just a matter of repetition of the moves that result in the reaction. Happiness, like martial arts, requires practice. Once the flow starts happening, the happiness rises to the top.