The historic Korean culture is focused on respect for elders and comes with a strong sense of discipline and humility. The people believe honor and respect comes with time, hard work, and a long process of learning. With this mentality also comes an effort to "save face," which is a desire to never offend another and gives people an opportunity to maintain their pride, which is something that takes generations, not years to gain.
Additionally, the Koreans have spent much of their history under foreign rulers and this, like it often does, created a stronger ethnic pride and identity. This united the people and soon the people began to follow any ethnic Korean at a point the communists, under the leadership of Kim Il-Sung, came to power. Kim's leadership was quickly accepted due to this strong national pride, his leadership, and his strong belief in self-rule.
Although historic Korean ideals allowed Kim to come to power, it was only Kim and his circle of leader that have altered the culture since this time, without the people's approval or, in many cases, knowledge. Kim and his government decided to isolate the people as their focus shifted to economic growth, however one-sided growth as industry became the only market exploited. They also isolated the people from those abroad, the country attempted to became self-reliant, and began to teach their people whatever is needed to maintain power and instill pride.
This isolated state has led to the people of North Korea being so isolated that they don't know any better than to believe what their government tells them is true; many of these people have been the victims of government lies from the day they were born. The people are too poor to afford cars or to travel with any significance as long bus trips, train trips, and flights are too expensive for anyone to even see their own country. Fear is an integral aspect of daily life so socialization has diminished as distrust has risen. Luxury goods are not accessible and, even if they were, no one would be able to afford them. Knowledge of the outside world is limited to misconceptions as fast food, packaged foods, and most technology are unheard of in this hermit state.
People everywhere only know as much as they are taught and the North Koreans only known what their government has told them, which is not always true. About the only aspects of the North Korean's historic culture that survive are their language, heated floors, a sense of respect, some clothing, and some foods.