I have read a
post on Quora that made me realise why the Japanese aren't as happy as they should for the level of socio-economic development, and despite being one of the healthiest and most peaceful nation on Earth.
This has to do with the Japanese concept of
gaman (我慢), which Wikipedia describes as "enduring the seemingly unbearable with patience and dignity". The term is generally translated as "perseverance", "patience", tolerance, or "self-denial". This form of stoicism pervades Japanese society. It is also linked to the expression
ganbaru (meaning "try hard", "do one's best", "tough it out", or "work with perseverance"), which the Japanese use all the time. This facet of Japanese culture is admirable and explains why Japan managed to recover so well after WWII and quickly became the world's 2nd economy. Unfortunately, on a personal level, living with gaman and having to "gambarate" (as I like to anglicise when speaking English with Japanese people) on a daily basis isn't the best way to achieve life satisfaction and happiness.
Add to this that Japanese people are very collectivist and constantly have to worry about what other people at school, at work or in society in general think of their every action. Japanese culture is all about preserving the group harmony, and this can only be achieved by keeping one's opinions to oneself. That is based on the Confucian concept of
honne vs tatemae (true feelings vs public façade). Because of this, most Japanese won't share their true thoughts or opinions with anyone else than close family members or very close friends. That can be a very lonely world, devoid of individual freedom. Self-denial, be it in enduring one's problems without complaining, working hard for the benefit of the group, and avoid burdening others with one's "selfish" opinions are all great to build an efficient society, but terrible for personal fulfilment and happiness.