Siren's Tail

Roque was disoriented. They told him that he was a human being and that he could become a mermaid. He didn't understand why it was one thing that had to become another. Also forever! One thing or the other. Black or white. Meat or fish. Boy or girl. Human or mermaid ... As if there were only two options! Can't a decision also be that you don't want to make a decision?