Whenever I think about Lucille Ball, I can't help but contrast her onscreen presence with her offscreen reality. On "I Love Lucy" she was convincingly middle-class. In real life, she always exuded extreme glamor, the kind of big-eyed, well-maquillaged, bouffant-type glamor that went out with Zsa Zsa Gabor.

Bill Cosby's dichotomy is similar: He's so approachable-seeming as Cliff Huxtable, but in real life he always feels austere and headmasterly. On "The Colbert Report" last night, we got to see a new kind of Cosbyesque austerity: the surreal comic. See if you can figure out what he's doing here. It's a trip.