World War I, which ended in 1918, had displaced nearly a million Jews and destroyed what remained of the provincial shtetl culture that had defined life for most Eastern European Jews for centuries. Goodman notes, "The fading of traditional Jewish society left artists like Chagall with powerful memories that could no longer be fed by a tangible reality. Instead, that culture became an emotional and intellectual source that existed solely in memory and the imagination... So rich had the experience been, it sustained him for the rest of his life." Sweeney adds that "if you ask Chagall to explain his paintings, he would reply, 'I don't understand them at all. They are not literature. They are only pictorial arrangements of images that obsess me..."