To laugh often and much ... this is to have succeeded. Probably not from Emerson: here's the full quotation and the story.
To have played and laughed with enthusiasm, and sung with exultation - this to to have succeeded.
Love well, laugh often and live well for Christ.
Laugh loudly, laugh often, and most important, laugh at yourself.
He burst into one of his rare fits of laughter as he turned away from the picture. I have not heard him laugh often, and it has always boded ill to somebody.
Live well, learn plenty, laugh often, love much.
Those who laugh often never grow old.