People who always feel jolly, no matter where they are or what happens to them—who have the organ of hope preposterously developed—who are endowed with an uncongealable sanguine temperament—who never feel concerned about the price of corn—and who cannot, by any possibility, discover any but the bright side of a picture—are very apt to go to extremes, and exaggerate with 40-horse microscopic power.

The Writings of Mark Twain (ed. 1923)