On a foggy July morning in Seoul, 76-year-old Moo-Dae was sitting on a bench in the belly of the Saejeol metro station when he felt the need to write a poem. In the humid summer heat, he was imagining a lonely winter scene: a woman sitting by a flickering candle in the 1970s, waiting for her husband to come home. “I wanted to write about loneliness,” Moo-Dae recalls a few days later, in his native Korean. His real name is Kim Seung-Yeul, but he prefers to go by a pen…