Same question for women. Gender is only useful insofar as we decide it is. We have an inherent nature to categorize and differentiate, and in some cases that makes a lot of sense, but outside of strictly biological facts, that distinction between genders is nebulous at best.

Like religion, gender identity is personal, even if it stems from society. No two people will share the same opinion, it'd probably be weird if they did, and as long as they're not using their opinion as basis for fact, do whatever you want, man woman or anyone in between, outside, or around the spectrum.