It seems you are right:
“The modern belief that especially medieval Christianity believed in a flat earth has been referred to as The Myth of the Flat Earth.[1] In 1945, it was listed by the Historical Association (of Britain) as the second of 20 in a pamphlet on common errors in history.[2] Several scholars[3] have argued that “with extraordinary [sic] few exceptions no educated person in the history of Western Civilization from the third century B.C. onward believed that the earth was flat” and that the prevailing view was of a spherical earth.[1]”
http://en.wikipedia.org/wiki/Flat_earth
Its good to be skeptical, even of the skeptic 😉
