The Cosby Show was once the most popular show on TV — until the parents starting acting all-knowing and wise. It was far more fun in the earlier years when it was more truthful: Sometimes kids are right, and often kids are willful and have a point. Now, along comes Are You Smarter Than a Fifth Grader? to remind us how smart kids can be. Probably it’s a hit mostly because of coming after juggernaut American Idol, but there’s also a compelling, endearing side, especially to children and adults who haven’t forgotten long-ago days when they were kids and not taken seriously. Suggestion: There’s a formula here. Have a sitcom with true give-and-take, not just with the precociously funny Jerry Maguire kind of mini egghead, but with real kids with real brains. And Moms who have dopey moments, too. Aren’t you sick of that old Hooneymooners-Flintstones-World According to Jim-Family Guy family where Dad’s fun-loving, sloppiness-is-OK side is treated as a symptom of his general stupidity? Everybody lives out some wisdom,  especially kids.