Good point. As someone who lived in Nanning (not Nanjing, Nanning is the province across is the one above the Vietnamese border, across from Guandong/Hong Kong), it is intriguing to me how few people know they border on almost completely separate languages.

I took time to learn Mandarin, and could string sentences together. I could not even say thank you in Cantonese, once, without others laughing at me. The Cantonese-speaking kids I knew just say just give up.

Then I moved onto Arabic, that is another fun story.