>>10647384I don't know the context that caused
>>10645061 to use it in this thread, but the meme in general is just the flip-side of "nihongo jouzu" meme. If you're not familiar with THAT, I don't know if there is a short explanation? I offer a long one, though.
Japanese people say "nihongo jouzu" to foreigners when you demonstrate the linguistic skills of a 3 year-old. Or of a 10-year-old. Doesn't matter. Even if you don't actually know Japanese, but you hack your way through a single grammatically-correct sentence from a phrase book, you might get a "nihongo jouzu". It means "skilled at Japanese" in Japanese, and is intended as a compliment. Coming from some Japanese, it is genuinely meant as a compliment! For others, it is more of a polite appreciation, kind of saying "thank you for caring enough to try to speak my language, rather than requiring me to use my equally-awkward English".
The average Japanese person may say that to someone once in a year, but as the foreigner in the equation, you feel like it happens all the time. That "shared experience" factor has made it into an inside-joke among Japanese-speaking foreigners.