Yeah I highly doubt you could “communicate fairly well” in Japanese after two weeks. You might have memorized some standard phrases, sure. But two weeks would not even be enough when going from Dutch to German or English to French.
My point with was actually that fairly well is too relative, same as learned a language. Languages are hard communication is easy, it takes way more than 100 weeks to learn Japanese, but I base it of my self.
It's unfortunate, but I think these "I learned x language in y weeks/months" memes are probably here to stay.
After spending the last year becoming technical (data science -> software eng) and seeing all those "I learned to program in 3 months and got a job at Google" videos, I'm convinced that this is just the dunning kruger effect of not knowing enough about the subject to understand how long it takes to become competent.
Furthermore the "I learned x in y time" meme is almost always perpetuated by false beginners. I remember seeing an "I learned Italian in one week" video where the guy actually knew some Italian beforehand. He also had previously learned fluent French and Spanish beforehand, so to say he learned Italian from scratch is a huge stretch.
