Heat is the degree of hotness or coldness of a body. Similarly happiness also has some degree. It is a measurable phenomenon, you can compare whether a person is happier or sadder than someone else. Thus it is something relative and thus must be some entity (need not be tangible) in the space time domain. Why do people say that one should try to be ever full of joy and happiness. Well consider smile its an indication (to some reasonable precision) of degree of happiness of a person. It is tough to be sad and smiling. Thus smiling is something to do with happiness. Now during smiling we use lesser muscles than while we are angry or sad thus in a way being sad disspiates energy while being happy conserves it. Thus happy state is a higher energy state. So is meditation (though the energy bar here is lot higher). A non-meditator vibrates at 300 cycles per second while a meditated mind vibrates at 200 thousand cycles per second. Thus by simple deduction the energy content(product of Planck's constant and frequency) is much higher for a meditated mind (assuming that we are in agreement that we all are nothing but bundles of photons) Consider food habits or drinking habits, people say that we sohuld always try to eat food that is easy to digest and we should drink a lot of water that makes digestion still easier. That again is to do with conservation of energy. Thus what people advise actually is to stay in higher energy state, well, whats good about this state. This state is nearer to the highest energy level, the level of consciousness. As consciouness encompasses everything thus is the ultimate storehouse of all the energy. Then again, whats so good about staying close to it. Well consider an electron as it takes some energy it gets into higher level then releases it and gets back to lower energy state, but if we keep on giving it energy quantum then it would predominently stay in the higher energy state. And if we are able to supply enough energy it would free itself from attraction of the nucleus. Similarly our aim is not just to stay in higher energy state but to give enough energy so that we are one day freed off bondage. Then why does nature wants to keep every thing in lower energy and higher entropy state. As that is the gross nature, which exists when people identify there body as their real being when they vibrate only at frequencies of gross matter, when their enrgy content is less while chaos content is more(entropy) but the subtle nature is higher energy and lesser chaos level, there are various such levels 3 to be precise. We being at the first. So does that mean that nature wants us to remain attached to gross self, well not really if you see the centrifugal force that keeps the electron in place, it is inversely proportional to radius of the shell. Isn't this ironical, the farther it goes the easier it gets for it to enter the electron gas. Had nature really wanted us to be firmly fixed in these shells the attraction should have been directly prportional to radius maybe. Nature wants it to get free! Thus the benefit of staying in somewhat higher energy levels is that it easier that way to pull ourselves out. Thus we can easily take in more energy then release it and so on the transitions would continue may be endlessly or we may somehow try to break free the last shell and get away from this attraction and repulsion for ever.
"There are two ways out of this building one is that scaffold and the other is in their custody which one u choose is a choice i leave to you!!".