Attributed to Aristotle in Diogenes Laertius "The Lives and Opinions of Eminent Philosophers" translated by C. D. Yonge and Henry G. Bohn (p. 188), 1853.
Mary Schmich (2012). “The Best of Mary Schmich: Selected Writings by the Chicago Tribune's Winner of the 2012 Pulitzer Prize for Commentary”, p.28, Agate Digital