If someone identifies as nonbinary or genderqueer, it means they don't feel like they fit into either the "male" or "female" gender categories.
Even though nonbinary people have gained more representation in mainstream media over the past few years, there are still a lot of misconceptions. For example, they're probably tired of people making assumptions about their sexuality based on their gender identity.
Perhaps they're frustrated with people not using their proper pronouns, even after they've stated them multiple times.
Or maybe they're tired of people making judgments about the way they express their identity through their physical appearance.
