When you've lived in Japan for more than 10 years, and have spoken the language for even longer, it can be a bit annoying to hear your friend with rudimentary Japanese being complimented on their Japanese prowess for simply saying 'Arigato'. I've since gotten used to it with the understanding that 'Nihongo Jozu' doesn't actually mean you're good at Japanese, rather it's an acknowledgment of the fact that you have some sort of ability in the language, however minimal.

Japanese people can be very quick to judge at times. They can also be very shallow, often complimenting people on their looks rather than achievements. I think the West is right in putting the onus on achievements, rather than vanity, as this is a better, and healthier, motivator for us as humans (reminds me of the tragedy of Betty Draper from Mad Men).

Which is to say, you can easily fool people with what I call the Kanji Conundrum. Learn how to write a very difficult word in Kanji, one common example is 鬱 うつ Utsu, which means depression. Learn this Kanji, then tell people you can write it, and they automatically assume you know all of the Kanji up to that one (in terms of difficulty), and that you have somehow mastered Japanese. Well, at least this works for a party trick, but I guess that's about all it's useful for.