American Archive of Public Broadcasting on Instagram: "Happy birthday to our favorite, not-so-imaginary, Mr. Snuffleupagus! When Snuffy was first introduced on "Sesame Street," he was meant to be Big Bird’s imaginary friend. But over time, the show’s creators realized the unintended message this sent: that adults might not believe children, even when they’re telling the truth. Executive Producer Carol-Lynn Parente explained, “The fear was that if we represented adults not believing what kids sai