“Happiness depends more upon the internal frame of a person's own mind, than on the externals in the world.”

“It's not what happens to you, but how you react to it that matters.”

“The happiness which is lacking makes one think even the happiness one has unbearable.”

“Happiness is the interval between periods of unhappiness.”

“Happiness... consists in giving, and in serving others.”

“Every gift from a friend is a wish for your happiness.”

“Satisfaction of one's curiosity is one of the greatest sources of happiness in life.”