One of my favourite bits of TOS is when Space Abraham Lincoln calls her a Negress, then apologises for being racist, but Uhura genuinely doesn't know what the fuck racism is.

Unlike Sisko, she's never studied history, so she doesn't even know Earth used to have that sort of bigotry. That's the sort of culture I aspire to be part of one day. One where racism is so dead that nobody knows what it is.