I take his idea of "fluency" with a grain of salt because he hasn't actually posted any videos of him speaking the language. Fluency is about "nativeness" (if

I take his idea of "fluency" with a grain of salt because he hasn't actually posted any videos of him speaking the language. Fluency is about "nativeness" (if I can create my own word here). It's being able to think in the language (rather than translating), about being able to express yourself in slang/sayings/expressions that you don't learn in textbooks, about the accent you speak in, and so on. In this respect I REALLY doubt he reached fluency. The reason why many people fail to learn a language is because they use textbooks, which mean well, but are never enough. With Japanese, it always seems to be the same where each chapter is about: - Vocab list - A passage to read - Grammar explanation - Exercises By the time you finish the chapter you would have understood a bit. The next chapter would do the same, but without refering to EVERY SINGLE vocab you learnt in the last chapter. Repeat this process and you're upto chapter 10 but can't remember most of what you've learnt from chapters 4, 5, 6 and 7. The reason why living in the country works best is because you're constantly surrounded by everything you're learning. The chapter isn't finished, it's constantly being rehearsed.