Mandarin or Cantonese? - Neither
Whenever you find out a person's ethnic to be Chinese, the instant question that arises is "Mandarin or Cantonese?" "Neither, I'm Fujianese." There are so many different languages in China that it can actually sum up to hundreds.
Having different languages also means having different family cultures. I, myself, have grown up very differently from other friends in Chinatown (even though we grow up in the same neighborhood). After Chinese New Year, me and my friends always had a little fun game of seeing who received the most money from their relatives. While all my friends received less than $500, I would always receive more than $1000, all of us being under ten years old. I grew up thinking that it was just because I was lucky or my relatives loved me more than theirs do.
Later I realized more differences, how my friends received material presents from their parents while my mother only gave me money. Asking my mother later about why I never received anything other than money, she said it was a family thing - where we'd always give money in the case that one of us didn't really want the present. Of course the better option would just to buy things with the money we get. Later when I made more Fujianese friends, I realized we all got around the same money, each year getting more while Cantonese friends received a much smaller amount. I noticed that even though it was just one category, "Chinese", we all had different backgrounds, Chinese New Year just being a short example.
But aren't there people who teach Fujianese? The Fujianese dialect is very different from the others, there isn't a way to learn Fujianese unless you were born Fujianese. Every Fujian family speaks the dialect differently, they're barely able to communicate with other Fujianese people outside the family (Think of it as speaking English with an accent to another person speaking English with an entirely different accent). Each family speaks the dialect differently, mainly because of their background and where their ancestors lived.
One of my best friends is somebody I'd consider fully immersed in Chinese language since she's grown up in a Fujianese family, yet learned Cantonese and Mandarin from her family. Talking to her in Fujian dialect is very troublesome since she actually uses all three languages in the same sentence. It's like trying to piece together a sentence when you only know the beginning and the end of a sentence. I'm not a fan of puzzles, so I just converse with her in English. It's kind of cool if you think about Fujianese as it being a secret language that only your family can truly understand to the full extent, but there are a couple of people who are able to understand all the different accents of Fujianese (so you have to be sneaky!).
Overall, if you haven't noticed it already, being simply "Chinese" is not the correct term for somebody's race. Speaking a different dialect sometimes can feel like you're a person of an entirely different race. Sure, I'm still Asian, I may look similar to people in China, but each Chinese person has a whole different story based on what family language they speak. I often go outside and grab a bite to eat, me and my friends noticing in Chinatown which stores are Fujianese, Cantonese, or Mandarin, solely based on the food they serve. The differences are small, but when you add them all up, they're really obvious. A simple dialect shouldn't define you so much, but since there are so many different dialects just within the world, it's the answer to who you are. "What dialect are you?" "I'm Fujianese."