"A Smile in the World". "Subject Three" is a popular dance on the Internet. Although its name is inspired by "Subject Three" in the driving test, it is not actually part of the test. This is a popular internet meme and dance form that quickly became popular after netizens shared a video of a couple’s wedding in October 2023. The original name of the subject three song is "A Smile in the World". It is a song written and composed by Zhu He and sung by Jiang Jiang. It was released on April 22, 2022 and is included in the album of the same name "A Smile in the World". This song was originally a dramatic Chinese style song with heroic lyrics. This song has been cleverly adapted, breaking through the traditional form of expression and transforming it into a musical work that is loved by the public. Its melody and rhythm have been given new vitality during the adaptation process, making it a modern pop music that crosses cultural boundaries and can be widely sung, demonstrating a unique cultural fusion and artistic innovation.