So often we spend out time wanting for ourselves. Wanting people to do something for us, wanting things, wanting attention, wanting love, wanting something. On occasion, when we do get those things it feels good. But just as often we find ourselves feeling disappointed, sad, even angry when we don't get those things and maybe even when we do get those things. But, that good feeling doesn't compare to the amazing feeling you get when you do something for someone else. When you have a part in helping someone else feel good, feel loved, feel special and important.
Then there is a day when you do something completely for the good of someone else and you understand what it meant to that person. That is a feeling so far beyond the good feeling that comes with getting what you want. That is an addicting feeling. That is simply knowing how good you made someone else feel. And that is what propels us to continue.
The more we do that the more it will come back to us.