>>NK leadership and people are not insane,<<
Well maybe, maybe not...
"South Korean sources claim that Kim Jong-Il was born on February 16, 1941, and that subsequently his "official" birth year was adjusted so as to be in harmony in terms of decades with that of his father, Kim Il-sung."
"Before his accession to power, Kim Jong-il was frequently accused of dishonesty, drunkenness, sexual excess of various kinds and even *insanity* [emphasis mine], particularly in the South Korean press. While this is not an uncommon pattern of behavior in the sons of dictators (see Vasily Stalin, Nicu Ceausescu, Tommy Suharto and Uday and Qusay Hussein), at least some of these accusations seem to have been fabricated by the Korean Central Intelligence Agency (KCIA) of South Korea.
Some of these stories, however, come from defectors from the DPRK whose accounts have some credibility."
http://en.wikipedia.org/wiki/Kim_Jong_Il