The only truly happy man is always a fighting optimist. Optimism includes not only altruism but also social responsibility, social courage and objectivity.
W. Beran Wolfe

Unless we think of others and do something for them, we miss one of the greatest sources of happiness.
Ray Lyman Wilbur

Those who are not looking for happiness are the most likely to find it, because those who are searching forget that the surest way to be happy is to seek happiness for others.
Martin Luther King, Jr.

Life begets life. Energy creates energy. It is by spending oneself that one becomes rich.
Sarah Bernhardt

Seek to do good, and you will find that happiness will run after you.
James Freeman Clarke

This is the true joy in life, the being used for a purpose recognized by yourself as a mighty one, the being thoroughly worn out before you are thrown on the scrap heap, the being a force of nature instead of a feverish little clod of ailments and grievances complaining that the world will not devote itself to making you happy.
George Bernard Shaw

The ready back gets all the loads.
Latvian proverbs

The true way to soften one’s troubles is to solace those of others.
Madame De Maintenon

No one can sincerely try to help another without helping himself.
Charles Dudley Warner

We cannot live only for ourselves. A thousand fibers connect us with our fellow-men; and along those fibers, as sympathetic threads, our actions run as causes, and they come back to us as effects.
Herman Melville