He was groomed from a very young age to be dictator. This quote, according to his aunt (mother's sister who helped raise him).
Quote:
Kim was given a general’s uniform decorated with stars, and real generals with real stars bowed to him and paid their respects to him from that moment on.
“It was impossible for him to grow up as a normal person when the people around him were treating him like that,” Ko said.
https://www.washingtonpost.com/world/asia_pacific/the-secret-life-of-kim-jong-uns-aunt-who-has-lived-in-the-us-since-1998/2016/05/26/522e4ec8-12d7-11e6-a9b5-bf703a5a7191_story.html?utm_term=.46fe67359ccb