Some of the things you learn from living in Japan come quickly and are like a culture shock slap to the face. Others take a long time to see and understand (and perhaps some things just never come). When you first arrive, there's novelty everywhere and you take note of all the quaint little customs that seem charmingly Japanese (e.g., bowing, the way business cards are dealt with). You also take note of how you are regarded as a foreigner in both favorable and unfavorable ways.
If you live here long enough (and are American) and are lucky enough to forget the rampant emphasis on materialism, success, and money that is a pervasive part of American culture, you might absorb some of the sense of contentment that a lot of Japanese people seem to feel with a life of moderate comfort. It's often said that the Japanese are a culture of middle class people with relatively few people who are seriously poor or very rich. While there has been an increase in the number of people who deviate in financial status from the median, it's still by and large the case that people are middle class.
After you associate with enough people, you see that most people aren't pining constantly for what they can't have. You don't see people struggling to keep up with the Joneses (or perhaps the Satos in this case) or attempting to define themselves by their possessions or their hobbies as much as you do in the States. Of course, there are otaku but they aren't a significant part of the population. They are simply the part which attracts a lot of media attention.
It seems to me after a lot of experience with Japanese people that the bar for contentment in this culture is set lower than the bar in the U.S. Of course, I could be completely wrong and it may be that modesty prevents people from talking about their more lavish possessions in which they take pride or that the people I associate with do not share their material desires or general dissatisfaction with their lifestyle to me. I believe this is rather unlikely though since students tend to reveal more to foreigners than they might to Japanese people because we aren't evaluating them by the same cultural standard as their peers.
Sometimes I think that the best thing that might have come from living in Japan is a sense of contentment with a more modest lifestyle and an almost complete loss of material longing. I guess this may simply be a function of age and not part of the culture rubbing off on me but there appear to be plenty of people my age back home who worry about being able to buy this or that or like nothing more than to talk about what they buy.