You say that you do not succeed much. Does it concern you enough that you do not? Do you work hard enough at it? Do you get the benefit of discipline out of it? If so persevere. Is it a more serious thing than to walk a thousand miles in a thousand successive hours? Do you get any corns by it? Do you ever think of hanging yourself on account of failure?
Henry David Thoreau (1817–1862), U.S. philosopher, author, naturalist. Letter, December 19, 1853, to Harrison Blake, in The Writings of Henry David Thoreau, vol. 6, pp. 222-223, Houghton Mifflin (1906).