In their cultural notes in
Sing Chinese, Cindy Mao and Ma Baolin explain that, just like the American song "The Cuckoo", this song mimics the sound of the cuckoo bird ("gu-gu"). According to a chines folk tale, cuckoo used to be a woman who had several kids. The kids were so lazy they never helped their mother do housework. One day the mother was sick. She asked the kids to fetch her some water to drink. But none of them listened. The next day when they came home after playing outside all day, their mother had become a cuckoo. She told them that since they wouldn't help her fetch water, she had to get water for herself. After that, she flew away. Never again did a cuckoo make a nest or care for little cuckoos.