What is of cultural importance?

I spent four years of college studying Japanese language and culture. Now, for a country that has a history spanning over 2000 years, that is barely scratching the surface, but I feel that I have a decent grasp on some of the basics. My time here in Japan is causing me to contemplate what it is that defines a culture. Some of what I think defines me as an American is not what the Japanese would consider to be a particularly important part of my culture. I was surprised to find that one of the high school girls in my taiko group did not know some of what I consider to be basic tenets of Japanese culture (her father was just as surprised that I knew and she didn't…it caused quite a stir).

Here is how this whole topic came up. We were leaving taiko practice on Monday and I overheard Nanba-san talking to young Takaya about giri v. ninjo. (quick and very simplistic explanation: under bushido, the samurai had to balance their giri (duty) and their ninjo (personal desires). Under most circumstances the ninjo lost, but a great many plays have been written about this struggle, generally involving a woman…)

I was listening in and was really shocked when young Takaya asked what those things were. My exclamations began a conversation about Japanese culture and I came to find that she also did not know about honne and tatemae (another quick and very simplistic explanation: honne is how you really feel about things, tatemae is the art of concealing what you really feel in order to gratify the feelings of others…in a nutshell).

When all of these things were explained she understood them, but everyone was really shocked that I knew about them. Now to me, these two concepts are part of the framework that creates "the Japanese culture." It brings up the interesting point of how foreign cultures are examined. What I find to be important to Japanese culture they don't necessarily notice it or give it a name.
On top of that, can you ever really understand a foreign culture, because you will always be looking at it from a foreign perspective? Maybe that is why I live here…because I am a masochist…and I enjoy inflicting on myself the one thing I hate the most: failure. It is the desire to succeed and challenge myself that keeps me going. I can never succeed at completely understanding Japanese culture…but is that my job? Is that my goal? I don't know yet.

But it does make me interested in maybe finding a way to enroll in a class on American culture or read books about American culture written by Japanese people. It would be interesting to learn how they perceive my culture. In fact I think that may be a good way to learn about my own culture, since I find it hard to even define my own culture. In that same vein, I think I should read books about Japanese culture from a Japanese perspective to balance the American education I have.