Mechanics of Self Perception
I noticed that the way I feel about myself is actually the way I think other people feel about me.
And the only way I know what others feel about me is the way I think about them.
So when you want to feel better about yourself, think about other people's well being. The more people's well being you can think of, the better you'll feel about yourself. Therefore, the way to feel the best about yourself is to think about the well being of everyone.
God wasn't kidding around while designing us and life.