Some people regard that happiness is crucial in life. At the same time, the meaning of the word "happiness" is diversified from business success to comfortable human relationship so that thinking about the concept is one of the classic and major human activities in philosophy and religion.
What kind of things people call their "happiness"? The simplest concept is based on basic human needs such as food, housing, health and money. These things are necessary to lead life whereas improving them are still not enough in some countries. If human become content with the basic needs, they tend to demand other kind of pleasure in their lives. As example of these advanced needs, it is common to accomplish social success, to acquire knowledge and to make gentle friends or family. I personally believe that one's cultural and religious situation have enormous impacts on his or her needs. In the United States, social or business success is one of the dominant dreams while it is peaceful family relationship in some Latin countries such as Latin America and Southern Europe.
On the other hand, there are some stoic countries which restrain human happiness. Japan and some East Asian countries can belong to this category. If someone feel happy, it is often symbolized as selfish or greedy involving negative meanings. Therefore, people try to keep their happiness secrets. To avoid causing others' jealousy or crushed by their gossip, it is considered as a very practical way to live in the communitarian countries. In other words, the adaptation to each cultures is the big factor in achieving their happiness.
In conclusion, the definition of happiness is much varied as well as cultural diversity. In general, happiness is said as a essential factor in human life while it does not have positive meanings in some country. I guess that the main factor of live a good life is compatibility with their environmental factors.