The common denominator of the concentration attainments is that we learn to get ourselves into states of consciousness that are some mixture of blissful and peaceful, as well as increasingly spacious and removed from our ordinary experience. These can be a source of happiness that is far more intense and predictable than the happiness found in the ordinary world, though these states, too, obviously end. Being able to access as much happiness and peace as we wish when we wish reduces our anger at the everyday world for not providing us with these, making us less needy and greedy.
