This should not come as any sort of surprise once you think about it. I was on the bus today and the woman behind me was blabbering to her very young children in Mandarin (and since I speak as well as a little boy, I could actually understand most of it). I assumed from the way that she slurred her syllables (pronouncing ‘is’ as ‘shr’ not ‘shi’) that she was from Taiwan, so I asked what part of the island she was from. She turned out to actually be from Fujian, but she could see my mistake, since Fujianese and Taiwanese culture were very similar.
Anyway, just a little anecdote. I thought it was interesting to find out.