For A-listers like Zach Galifianakis and Sarah Silverman, Stevens wasn’t just a friend, he was a comic savant, one of the few acts they would drop everything to watch — leaving them to wonder: Why did he take his own life just as his career was heating up?

Replacing Jon Stewart on 'The Daily Show' seemed like a suicide mission, but nearly four Trump-filled years in, the biracial South African star has become a best-selling author and a household name in U.S., all while keeping up a grueling stand-up schedule: “When there's no conflict, pain or tragedy, I don't know what to do."