This was the game. In the real world, I was lying on the sloping edge of Melton Leisure Pool sometime in the 1980s, shuffling my child body down into the water; in my imagination, I was on the sea shore and the irresistible ocean had come to take me and make me a mermaid. It was a game played entirely alone, because its object was utter and perfect passivity.
Some people never stop playing mermaids. At conventions such as Mer-Mania in North Carolina, Merfest in Florida, or Merfolk UK, hundreds of adults gather to, as the Merfolk website puts it, “transform [themselves] into a magical mythical being from the depths of the ocean” and swim with the “Mer-community”. (These gatherings are not uniformly idyllic: Mermania 2017 was reportedly riven with cyberbullying and physical confrontations between merfolk, leading to the Mail dubbing it “the DARK SIDE of the real-life mermaids”.)