The Muppets are connecting generations with each passing decade

Has anyone ever felt old when you speak of a show that a younger generation knows nothing about? We can all think of some but one that does not fit that category is The Muppets. They appeal to young viewers as well as mature audiences from appearing on "Sesame Street" in the 1960s to their new show "The Muppets" on ABC. Jim Henson created The Muppets in 1955 and 60 years later it is still as popular as ever. What is it that makes The Muppets so appealing to all audiences and in different but appropriate ways? Is there a science to it? Can any show do it?