As you start to get into that space, you naturally get rid of your selfishness, you start to experience fulfillment. And in being fulfilled you become happy. The process doesn't identify I am going to get happy. It is though important to know that is part of what is going on. That the better you practice altruism, the better and more naturally you are happy.
True altruism is like the ultimate of openness.
It is not easy to practice. But in striving toward that, in trying to set up that sort of internal attitude within yourself, you will get happy, you will get rid of your suffering, you will get rid of your selfishness, you will become more happy, meditative, more serene, tranquil. But it is going to be in a way that it doesn't have any negative kickback. It doesn't have that somewhere in there it didn't quite make it. And in the Mahayana teachings we say spirituality which is aimed at personal fulfillment is a limited trip.