2.
Laugh loudly, laugh often, and most important, laugh at yourself.
Chelsea Handler
4.
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.
Arthur Conan Doyle
5.
To have played and laughed with enthusiasm, and sung with exultation - this to to have succeeded.
Ralph Waldo Emerson
7.
To laugh often and much ... this is to have succeeded. Probably not from Emerson: here's the full quotation and the story.
Ralph Waldo Emerson