For most of his life, Cosby has been riffing, improvising, playing off audiences and other performers, all the while making it sound like he knew where he was going all along. When he hit the right groove, Cosby broke new ground: as a comic who pushed standup comedy from jokes to storytelling; as the first African-American actor to star in a prime-time television drama series ; as a leader in educational TV ; as the world's No.