The ultimate source of a happy life is warm-heartedness. This means extending to others the kind of concern we have for ourselves. On a simple level we find that if we have a compassionate heart we naturally have more friends. And scientists today are discovering that while anger and hatred eat into our immune system, warm-heartedness and compassion are good for our health.
Dalai LamaThe more you think about your own self, the more self-centred you are, the more trouble even small problems can create in your mind. The stronger your sense of 'I', the narrower the scope of your thinking becomes; then even small obstacles become unbearable. On the other hand, if you concern yourself mainly with others, the broader your thinking becomes, and life's inevitable difficulties disturb you less.
Dalai Lama