Karius og Baktus began as a Norwegian children's story by Thorbjørn Egner about two tooth trolls living in a boy's mouth, and the characters later became widely familiar through an animated film adaptation. In Norway the pair remain a well-known part of childhood, associated with toothbrushing and dental care. Online, short clips of their voices circulate among Norwegian speakers as nostalgic soundboard sounds, and this sorrowful line is reused to add a small, childlike sadness to memes, reaction videos and everyday fail clips.