When French photo collector Jean-Marie Donat stumbled upon his first vintage picture of a German dressed as a polar bear, he initially thought it was just an odd historical anomaly -- at least, that is, until he found a second one. And then a third. And on, and on. Eventually Donat realized he'd stumbled across a bizarre photo trend: For decades Germany was obsessed photographs of people dressed as polar bears. So how did this trend get started, and why did it disappear? Listen in to learn more.