One of our strongest temptations in this life is to put ourselves first - to look out for "number one." We become convinced that the only way we'll be happy is if we're getting what we want. However, we have centuries of history and our own personal experiences that beg to tell us differently. When have we or anyone else found a lasting and peace-producing joy through acting selfishly?
Christ taught, "For what is a man profited, if he shall gain the whole world, and lose his own soul?" I will not attempt to interpret what the Savior meant by losing our soul but I think we have all felt our soul diminished when we have acted selfishly. Conversely, I know I have felt my soul magnified when I have acted out of love for another, placing his or her needs before my own.
I remember one day arriving at work in a rather bad mood. I don't remember what I was concerned about, but I must have been entertaining some kind of fear great or small (are all bad moods tied to a form of fear? I think so...). I thought to myself, "man, I need to help someone because I am worrying way too much about myself right now!" Just then I thought to stop in and see how a coworker was doing. He was doing well but needed some help moving some equipment. That was easily done and I left the room feeling much better! Victory! Bad mood banished.
This is one of many such experiences I've had getting outside of myself and finding relief from the temptation to be selfish by helping someone else. Chances to do so are all around us! President Dieter F. Uchtdorf emphatically stated, "My dear brethren, there are so many people in need whom we could be thinking about instead of ourselves. And please don't ever forget your own family, your own wife. There are so many ways we could be serving. We have no time to become absorbed in ourselves."
Selfishness creates misery, and is terribly tempting, but can be overcome. Elder Neal A. Maxwell quoted Joseph Smith saying, "Let every selfish feeling be not only buried, but annihilated." We can do so. We need only turn our attentional compass from S to N - "Self" to "Neighbor."