People rarely succeed unless they have fun in what they are doing.
Dale Carnegie (1888-1955) American writer.
Horse-play, romping, frequent and loud fits of laughter, jokes, and indiscriminate familiarity, will sink both merit and knowledge into a degree of contempt. They compose at most a merry fellow; and a merry fellow was never yet a respectable man.
Lord Chesterfield (1694-1773) British statesman.
If you do not feel yourself growing in your work and your life broadening and deepening, if your task is not a perpetual tonic to you, you have not found your place.
Orison Swett Marden (1850-1924) American author and founder of Success magazine.
Fun is a good thing but only when it spoils nothing better.
George Santayana (1863-1952) American philosopher and poet.
Fun I love, but too much fun is of all things the most loathsome. Mirth is better than fun, and happiness is better than mirth.
William Blake (1757-1827) British poet and painter.
All animals, except man, know that the principal business of life is to enjoy it.
Samuel Butler (1612-1680) British poet and satirist.