The line comes from Green Eggs and Ham, the 1960 Dr. Seuss picture book built around a narrator who refuses to try green eggs and ham. Sam-I-am spends the whole story offering the dish in every setting until the narrator finally tastes it and likes it. The refusal has become one of the most quoted lines in children's literature, and clips of it circulate online as a firm no for food challenges, picky eater jokes and taste-test videos. Its staying power comes from the simple rhythm and the universal experience of refusing something before trying it.