I am astonished at the singular pertinacity and endurance of our lives. The miracle is, that what is is, when it is so difficult, if not impossible, for anything else to be; that we walk on in our particular paths so far, before we fall on death and fate, merely because we must walk in some path; that every man can get a living, and so few can do anything more. So much only can I accomplish ere health and strength are gone, and yet this suffices.
Henry David Thoreau (1817–1862), U.S. philosopher, author, naturalist. A Week on the Concord and Merrimack Rivers (1849), in The Writings of Henry David Thoreau, vol. 1, p. 311, Houghton Mifflin (1906).