Can people really consciously choose who they are sexually attracted to? I haven't been able to chose to be sexually attracted to someone, ever. I either was or I wasn't, that could be slow but in it an explosion, but it wasn't a choice. Choice only comes in for me when I've chosen not to act on it, which is different.
I don't just feel I'm attracted to someone, I am. It's a biological reality too - I bet if you measured my heart rate etc when I was in close proximity to someone I'm attracted to, it would be different than someone I just like. And, if I'm attracted only to women, that makes me a lesbian. I'm not feeling like I am a lesbian, it's a label applied as a byproduct of same sex attraction, which is uncontrollable.
I have heard the argument that you can think yourself (choose to be) a lesbian, but I don't believe it. If you're a heterosexual woman who finds you are also attracted to other women, then you're bi, not heterosexual - just like a lesbian who is attracted to men. And due in part to the impact of social conditioning, that can be something that doesn't manifest until later in life. So rather than choosing to be lesbian, women who "choose" to be attracted to other women are perhaps choosing to walk through a door they hadn't previously realised was open to them.
As for biological sex, may feel like I'm a man, but that cannot ever make me one. The label "man" is not a feeling (although there may be feelings associated with it), it's a biological fact. It's not retroactively applied depending on how I feel.
Non-binary (as one of the millions of gender identities, including the gender identity of man and woman, as based on stereotypes, not biology) are also not biological realities, they're based on feelings: labels applied to how someone subjectively measures themselves against what they interpret as societal norms.
In the case of gender dysphoria, the feeling of being aligned with the opposite sex may be very strong, but it couldn't even exist if your sex was determined by how you feel. It illustrates that saying "I am a woman" as a biological male is incorrect but "I feel like I'm a woman" could be a true statement. And someone easing that discomfort by having surgery to make the like the opposite sex isn't a lie. It's not saying they ARE the opposite sex.
The point of my initial post was really that we have kids going to therapists (or parents or teachers) saying "I am [opposite sex/gender identity]" and were there a strongly applied basis upon which to respond "You feel you're X" the situation would be very different than "Oh yes, you're a boy then" (in the case if girls. If children are trained to distinguish between feelings and facts then they have the opportunity to live a much more emotionally comfortable life with regard their own self-concept.