I was brought up speaking Singaporean hokkien. When I moved to the US, I had no problem understanding or conversing with hokkien people from Penang. Except for some variance, I hardly knew it was a different language. But when I moved to Mankato Minnesota, I met 20 over Indonesian students from Medan. I tried conversation with them but over the course of two years, I ended up learning a completely new language (Medan Hokien). Fortunately, I speak Malay and Indonesian and so I was able to pick up what they say whenever part of their language is non-hokkien. But I must say, a typical Penang or Singaporean hokkien person will have a very hard time understanding beyond a few words every sentence in Medan hokkien (Medanese Hokien?).
I must say, it's even harder for me than the last time (whilst travelling in Taiwan) when I fake myself as a local Taiwanese speaking Taiwanese Hokkien. After learning from Wikipedia that Medan hokkien is from 漳州, and after checking their geographical location from my ancestor, and talking to my 92-year-old granny explaining how far 漳州 was when she was a kid and how nobody could understand them, it sort of explains. Now I am 45 years old. I'm still struggling to teach myself Japanese, and I'm seeing so many sounds in Japanese that sounded just like hokkien (e.g. counting from 2 to 6, "music", "dried shrimp",...)
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