I mean, what if a woman laughed and was like "Oh, LOL, you're a man? I didn't notice!"
Shift the context just a little, and people will take it as an insult. NOT NOTICING who people are isn't flattering, it isn't nice, it isn't post-racism. It's just being a dick, unless you authentically have brain damage or a disorder that makes it difficult for you to perceive physical attributes of individual people.
I wouldn't be insulted by that.
I'm not saying I don't notice who people are, I'm saying I notice what people do sooner than I notice a haircut. Do not assume that my lack of interest in looks only extends to those looks that are different than mine, I don't give a fuck about my own looks either.
I have similar blocks regarding money, I don't notice the price of some rich asshole's clothes, I notice them acting like they are better than other people.
I don't have brain damage, I have self-built mental blocks that keep me from perceiving trivial attributes of people such as minor variations in looks.
People for whom superficial traits are so essential to their identity that they feel insulted if others aren't constantly noticing those traits are difficult for me to understand. Don't these people have hobbies?
Maybe this would help clarify:
If someone sees you sitting and reading, would you prefer a question about your thighs or about your book?
Sorry, it's just a pet peeve of mine. White men tend to be the worst, because they assume that thinking you're just like them is some kind of compliment, like "Oh, I didn't even notice you were brown or female" is supposed to make me feel GOOD about myself.
No need to apologize, I knew that beforehand.
Oh, relevant! I would notice your
skin and gender because it is a large part of your self-image. I would still care more about your study books and be more likely to remember titles of your books than the length of your hair a few days (or even minutes) later.
If that is generally considered offensive, I still won't change that part of me. I am an anti-social bibliophile and a boorish bastard.