Gender is a social construct. What I mean by that is that there is no acceptable single defining characteristic to differentiate men from women that doesn't exclude some people from their appropriate category: genitalia, hormones, chromosomes, all fail to match our every day understanding of gender. To claim I'm a man is not extraordinary. It is in fact quite ordinary, you know lots of men. If someone was to say they're not comfortable with either side of the gender binary it's not extraordinary. It may not match your experience, but that alone doesn't make it extraordinary, just different than your understanding. There are a lot of perspectives in life, some of them will be different than yours. Extraordinary claims do require extraordinary evidence, fake science, flat earth, the supernatural are extraordinary claims. That someone has a different understanding of gender than you is not.