Many people recognize that gender – how a person identifies, presents themselves and is perceived – has nuances. Some people identify and present as women, others as men, and still others as nonbinary.
But there is a common misconception that biological sex – usually determined by a person’s sex chromosomes, gonads (ovaries or testes) or genitals – is binary. This idea assumes that everyone is biologically either female or male, with no ambiguity or intermediacy.
Well, it would be more disturbing in the sense of what a society is that forces this. Also, there is a very famous case of a person removing their appendix in the past, a fascinating story in a way: https://en.wikipedia.org/wiki/Leonid_Rogozov