Robin Williams is seen here on his way into last night's "Late Show with David Letterman" wisely pairing a natty gray suit with the latest in Korean women's outerwear and some sort of knapsack fashioned together with a seatbelt harness. You know, I just realized that it's going to be nearly impossible to tell when Robin Williams makes the transition from "eccentric retardation" to "garden variety senility." Someday he'll just be working on the set of a film and people are going to be all, "Holy shit! Did Robin Williams just poop in his pants?"