"Gradually I learned to be indifferent to myself and my deficiencies; I came to centre my attention increasingly upon external objects: the state of the world, various branches of knowledge, individuals for whom I felt affection." -Bertrand Russell
I came upon this quote in Mihaly Csikszentmihalyi's book, Flow, and I think it may be the key element in reducing stress while increasing happiness and success. It ties together other books I've been reading, like Mindfulness, How to Win Friends and Influence People, The Joy of Living, Why Zebras Don't get Ulcers, The Happiness Hypothesis, Who Moved My Cheese, Switch, and Drive, and distils out one of the key elements of them all:
The more I can forget myself and really focus my attention on other people, greater purposes, tasks I can master, sounds, tastes, smells, images, experiences around me, the happier I'll be, and the more successful I'll be at teaching, leading, and everything else.