Except that we really don't know it. If you come to think about it, we're extremely well-informed about the habits of one of the most isolated regime's leader, which is kind of self-contradictory. The reason is that most of these gossips are firstly reported (and sometimes invented) by South-Korean tabloids and propaganda tools and quickly adopted, without any critical examination being deemed necessary, by more respectable media outlets, which hope to appeal to the audience's patriotism and thirst for cheesy events based on the inaccurate stereotypes of dictatorships being inherently irrational, in order to generate more views for their content. A typical example is the rebirth of general Ri Yong-gil, who turned up
suspiciously healthy in his party's congress, considering he was supposed to have been executed a few months ago.
Anyway, more on topic, North Korea's nuclear project is a perfectly reasonable initiative from their perspective, essentially designed as a defensive measure. The government is completely aware that the steadily increasing technological gap between her and her enemies means that her conventional military equipment becomes gradually obsolete and useless. Therefore, their only hope of survival is to invest on assymetrical warfare, hence the focus on nuclear weapons, with the goal of preventing any potential offensive operations, on behalf of the United States or South Korea. Theoretically, a second alternative also exists: Namely the abandonment of their nuclear project, in exchanged for a favourable diplomatic deal, whose terms would guarantee a peaceful coexistence. However, the North-Korean leadership has obviously viewed such an option as totally unrealistic, a conclusion stemmed for rather convinving arguments, in my opinion. Once you ditch your only bargaining chip, your geopolitical position becomes very fragile, as the examples of Iraq, which was invaded under a fabricated pretext, and Libya, where Gaddafi was overthrown and eventually lynched by the mob, despite his previous cooperation with the western authorities prove.
Especially the bombing of Libya was absolutely catastrophic not only for the stability of Libya and her neighbors, but also for the United States' international reputation. It is not a coincidence that North Korea's nuclear activity peaked up exactly after the end of operations against these two countries. This is why the current moment is so tense, because we are in a transitional stage, just before North Korea becomes capable of dramatically improving her military efficiency and, consequently, her prospects of survival.