Happiness is the umbrella experience for a number of other experiences of which connection may be most important. The "other" is support, comfort, delight, a mirror and a promoter of growth and change only if we can connect with her. This is one reason why all religions teach compassion, promote love, and charity.
When I was young, I was taught to love everybody like a brother or a sister, especially the disadvantaged. My compassion grew in accord with my awareness, but instead of this causing happiness only, it also caused unhappiness. There seemed so little I could do. I felt overwhelmed. "But there is so much you are doing," some nice people would say, "You are making a real difference. Everything has a snowball effect even when you cannot see it." That helped, I must say, until I saw another suffering being. What had gone wrong?
Caring about others takes a lot of inner strength. Before we have that inner strength, compassion can burn us out and up. That inner strength grows slowly. And only when we are recipients of compassion, have learned to be kind to ourselves, and have cultivated a sense of inner peace and tranquility, will it cause happiness. The more peaceful we grow, the greater the space for Being, no matter how Being is expressed.
Quietly we can sit, accepting the world 'as is', surrendering to what we cannot change, never becoming tired to changing what we can change. A compassionate heart needs to be held by something even greater, something we can only deeply experience when we are still, something that is always good and never lets us down, which some call God or the hand of God, and others Being, or the One to which we all belong.