Despite its sunny surface, “optimism” originated in a darker place. Mr. Seifer was inspired by a maxim he found printed on a Domino’s sugar packet: “An optimist is someone who tells you to cheer up when things are going his way.”
An undergraduate at the time, studying art at Clark University, Mr. Seifer incorporated the phrase into his senior thesis, which focused on an incident with his father, who once offered an empty soda bottle to a homeless man collecting cans for redemption. The man refused, finding the offer patronizing.
http://www.nytimes.com/2009/11/20/nyregion/20metrocard.html?_r=2&hp