What does 'to identify as' really mean? I could identify as a knowledgeable bird-fancier to my friends as I have begun to learn more about them for the last couple of years, but I would never go to expert bird-fanciers' groups and tell them that I am someone on their level of knowledge when I am not.
They would see through my presumed identity as not matching facts. My friends know that I'm actually not a bird-fancier, but now interested in and learning about them, so they interpret my identity claim more kindly, as they would interpret most similar claims which don't damage others or me kindly.
The gender identity ideology if it included being an expert bird-fancier as a gender would argue that everyone in the whole world should take my bird-fancier self-identity as a fact, or at least pretend to take it as a fact.
This is what they are doing for gender identities, and because most people do know this difference in how we treat 'identity' in different contexts, they try to make it impossibly punitive not to obey them.
So outside circles of friends, 'identity', for it to have relevance, must have some external verification. If you identify as a Norwegian, then you should know quite a bit about Norway, you should have lived there or if not that, then to have had at least one Norwegian parent.
And clearly we can't identify as neurosurgeons if we have no qualifications in that field, because the consequences for others are so severe.
If I apply this test (existence of facts to support the identities) to gender identities most of them fail it right away, and only a handful is left for closer scrutiny. (Note that this is not about replacing sex with gender identity, but about when to even take someone's assertion of an identity at all seriously, as a starting point to be interrogated further.)