I was born in India and moved to the United States when I was very young. One of the other Indian-American kids asked me what my caste is after hearing my unfamiliar last name. At the time, I hadn't even heard of caste, and didn't realized what kind of parenting environment creates a 7 year old (who doesn't even live in India or speak the language) to question the caste of another Indian in the first place. After sch…
In India, there are egregious things reminding you about it, i.e. literally every government form ever -- but in the US it's reasonably easy to ignore and forget about completely unless you go out initiating conversations about it, or are unlucky enough to run into someone like your friend.
I have had a ton of both Indian-American and Indian immigrant friends in the US, and have had zero conversations with any of them that involved discussing caste.