Ai Weiwei is probably China’s most famous contemporary artist and activist. His new memoir, “1000 Years of Joys and Sorrows,” is a parallel story about his own life and that of his father, Ai Qing, one of China’s most renowned modern poets. Growing up during the Cultural Revolution with his father a target of the Communist authorities helped turn Ai Weiwei into a staunch defender of freedom of expression at whatever cost. The World’s Carol Hills speaks with Ai Weiwei about his father’s remarkable life.