From The Great Successor: The Divinely Perfect Destiny of Brilliant Comrade Kim Jong Un, by Anna Fifield (PublicAffairs, 2019), Kindle pp. 50-52:
The apartment on Kirchstrasse was more modest than what he was used to back home, but Kim Jong Un could live a relatively normal existence there. And he could devote himself to his favorite pastime: basketball. It was his mother who first sparked his interest in the sport. There’s an old tale that Korean mothers, North and South, like to tell their children: if you play basketball, you’ll grow taller.
Kim Jong Un was short as a child, and his father was not a tall man—he was only five foot three, and famously wore platform shoes to try to compensate—so Ko Yong Hui encouraged her son to play basketball in the hope the tale was true. He grew to be five foot seven, so maybe it worked a bit.
She was thrilled to see her son taking to basketball, a sport that she believed would help him clear his mind and loosen his childhood obsession with planes and engines. Instead, Kim Jong Un’s mother and aunt soon saw that basketball had become an addiction too—the boy was sleeping with his basketball in his bed—and one that came at the expense of his studies. His mother would visit Bern regularly to scold her son for playing too much and studying too little.
She arrived on a passport that declared her to be Chong Il Son, assigned to the North Korean mission at the United Nations in Geneva since 1987, but the Swiss knew exactly who she was. After all, she arrived in the country in a Russian-made Ilyushin 62 jet bearing the insignia of Air Koryo, the North Korean state airline. The plane, which bore the tail number P882, was for VIPs only. It even had a full bedroom onboard.
All sorts of bags and merchandise would be loaded on and off the plane, watched carefully by Swiss intelligence. They monitored Ko Yong Hui closely, keeping records of everything from her shopping expeditions on Zurich’s Bahnhofstrasse, one of the world’s most exclusive shopping avenues, to her hospital bills at fancy private clinics on Lake Geneva.
They also knew who her children were. They called Kim Jong Chol “the tall, skinny one” and Kim Jong Un “the short, fat one.” But the new Swiss attorney general, Carla Del Ponte (who would later become chief prosecutor in the international criminal tribunals on Yugoslavia and Rwanda), had forbidden the Swiss authorities to monitor the children. In famously discreet Switzerland, they were allowed to just be children—even if they were the children of one of the world’s most notorious tyrants.
When Kim’s mother arrived in Bern, she would bring handwritten notebooks containing one thousand Chinese characters, which form the basis of most Korean words, that she had made and photocopied so the children could keep up with their language skills. She told her sons that they had to memorize five or six pages a day, the kind of homework that torments Korean children the world over.
She was what we today would call a tiger mother, pouring a lot of energy into her children’s education and going through their journals and homework no matter how late she returned to the apartment at night.
But Kim Jong Un had other priorities.