The line comes from 'The Wonderful Thing About Tiggers', the Sherman Brothers song that debuted in Disney's 1968 featurette Winnie the Pooh and the Blustery Day, where Tigger introduces himself to Pooh with a bounce. Sung by Paul Winchell in the original short, the tune became one of the franchise's most quoted moments and a staple of nostalgic meme edits and reaction videos. Like the Woody Woodpecker laugh, it survives because a single bouncy phrase carries an entire character's personality.