Mark Twain (2014). “Mark Twain on Common Sense: Timeless Advice and Words of Wisdom from America's Most-Revered Humorist”, p.53, Skyhorse Publishing, Inc.
Attributed in Reader's Digest, Apr. 1934. A similar remark, attributed to an anonymous octogenarian, appears in the Washington Post, 11 Sept. 1910. See Jefferson 42
Mark Twain (2014). “Mark Twain on Common Sense: Timeless Advice and Words of Wisdom from America's Most-Revered Humorist”, p.37, Skyhorse Publishing, Inc.