Eleanor Roosevelt on happiness

Happiness is not a goal, it is a by-product. Paradoxically, the one sure way not to be happy is deliberately to map out a way of life in which one would please oneself completely and exclusively. After a short time, a very short time, there would be little that one really enjoyed. For what keeps our interest in life and makes us look forward to tomorrow is giving pleasure to other people.

Eleanor Roosevelt, You Learn by Living: Eleven Keys for a More Fulfilling Life (New York: Harper & Row, 1960).

Also from this book
On doing what you think you cannot do : On honoring the human race : On attention : On maturity : On optimism