Suppose you are Kim Jong Un. You are in your late twenties, similar in age to a typical entry level associate at a big law firm or medical resident or mid-career NCO in the military.
This week you have just inherited from your father (deceased at age 69 or 70, who was somewhat unbalanced and not the world's nicest guy) an entire country with twenty four million people, substantial territory and nuclear weapons on missiles at your disposal to rule as an absolute dictator, without even having to ask for campaign contributions or filling out a job application.
How do you feel about that? Are you overjoyed at your newfound power? Are you mostly consumed with grief over your father's death? Are you ticked off that your father totally screwed up your country causing millions of its people to die of starvation and the vast majority of the rest to live totally backward lives and then gave you the mess to clean up? Are you terrified that you'll screw up given your responsibilities? Are you terrified that you'll be assassinated by someone close to you before you have a chance to consolidate your authority? Do you seriously consider abdicating and letting someone else deal with it, after all who made it your problem?
By all accounts Kim Jong Un is a much more decent and sane person than either his father or his grandfather who preceded him in office (or than his older siblings who were passed over for the job after having amply demonstrated what losers they were), although not necessarily so charismatic. Do you worry that you aren't ruthless enough for the job? Do you try to act crazy and ruthless because you think you must to be taken seriously? Do you undermine your own power structure for the benefit of your people, knowing what works in other countries, or do you feel the need to enhance your own personal cult of personality in order to gain the clout in de facto power you need to institute major reforms? Do you follow the precedents and policies established by your father and grandfather, imitate the systems of places like Switzerland where you received some of your education, or try to devise some third way specific to your inclinations and local conditions? Do you submit to being a figurehead for your elders and late father's flunkies who wield power more directly and have more experience, or do you make your own decisions? Just because you've grown up around immense power doesn't mean that you know how to wield it yourself. Do you put your friends in power, or people you think you need to have support you? Do you indulge yourself with creature comforts attendant upon your new office, or throw yourself into a spartan life full of work? How do you date somebody?
This isn't quite a Princess Diaries moment. Your didn't grow up in some peasant household oblivious to your place in the society. If you are Kim Jong Un, you've known this day was coming for years, have lived your entire life in your father's inner circle which is the pinnacle of all political and economic power in the country, and have already had some close calls when you were nearly pushed into the job after your father's other health emergencies. Surely, you've spent a great deal of time thinking about this day. What kind of plans and expectations did you form in advance? Which of them will still seem to make sense now?
There is some reason to have optimism for the long term. While the early years of the rule of young, absolute leaders of countries has historically been a mixed bag, the ranks of the truely outstanding absolute rulers of nations are disproportionately made up of people who inherited the office at an early age, not people who took office after decades spent in an understudy role. Perhaps if you start young you have more time to learn how to do the job well and more of a stake in your long term success. We'll soon see how Kim Jong Un compares.