(Wally Santana ~ Associated Press)
"What I miss -- and what I still vividly remember -- is when I got together with my friends on my way to school in the morning and the shouting and fun we had as we walked to class," he said.
But for 55-year-old travel agent Kim Jung-yeon, the prospect of Kim's untested, 20-something son leading North Korea is cause for fear, not optimism.
"He knows so little about the world," she said Tuesday, "so he may be even more dangerous than his father."
South Koreans, who have the biggest stake in their northern rival's stability, wait nervously to see what the change in leadership in Pyongyang holds for them: whether it paves the way for reconciliation, or leads to further instability and conflict between the bitter enemies.
On the streets of the South Korean capital, many have firm feelings about both possibilities.
"North Korea will continue its menacing threats and it will again launch a provocation" like the two attacks blamed on North Korea in 2010 that led to fears of another war on the peninsula, said Kim Jong-sun, an 86-year-old Korean War veteran with a heavily wrinkled face, as he strolled through a Seoul park.
"They won't abandon their belligerent war threat, and we have to live with such North Korea fears."
North Korea has always been an uneasy presence for South Koreans. Even as the South has transformed from autocracy and poverty to a booming economy and vibrant democracy, the nation ruled by Kim Jong Il and his father has often seemed to outsiders as a vestige of the Cold War, beset by chronic food shortages.
But these two enemies have a shared history, a shared culture, and even families split on two sides of the world's most heavily militarized border.
"We are one nation, and I hope we achieve reunification," said Lee Ae-young, a 49-year-old professional photographer in Seoul. "I don't know why we are living like this, divided along the border."
Seoul is only 120 miles from Pyongyang, but they are separated by bitter differences and a long history of bloodshed. The peninsula is still technically at war because the devastating 1950-1953 Korean War ended with an armistice, not a peace treaty, and for the past 17 years, Kim Jong Il has been an omnipresent, often threatening figure, for South Koreans. He took power in 1994 after spending 20 years preparing for leadership.
Kim Jong Un has had no such lengthy transition, and little is known of him, the policies he might set or even his exact age.
Despite their worries, South Koreans aren't panicking this week, as they did in the past. Many rushed to supermarkets to stock up on instant noodles and other provisions after Pyongyang abandoned an international nonproliferation treaty in 1993 and North Korea founder Kim Il Sung -- Kim Jong Il's father -- died of a heart attack the next year.
Since then, many South Koreans have grown accustomed to having a rival on their doorstep and have been lulled into a confidence that the skirmishes between the neighbors won't escalate into another war.
"It's unlikely that North Korea would stage a full-blown war," said Kim Jung-yeon, the travel agent, "because it would be a burden for them" to fight.
Analysts say Kim's death won't plunge the country of 24 million people into chaos anytime soon or lead it to provoke South Korea.
"It's unrealistic to talk about North Korean provocation now ... as they are engulfed with sadness," said Cheong Seong-chang, a senior fellow at private Sejong Institute in South Korea.
"Those close to Kim Jong Il and Kim Jong Un have a grip on the North's military and security. ... It's difficult to imagine there would be any organized resistance by the public," said Cheong, who has followed the North's succession issue closely for years.
In a conciliatory gesture apparently aimed at keeping tensions low, South Korea's government offered sympathy to North Korea's people Tuesday and said it hopes Pyongyang will cooperate with Seoul for peace and prosperity on the divided peninsula.
Unification Minister Yu Woo-ik told reporters he will ask Christian groups to refrain from lighting giant steel Christmas trees near the border with North Korea, acts that the North views as propaganda warfare.
For Kim Yu-sik -- the 75-year-old from a city just west of Seoul -- his homecoming to that town outside the North Korean capital seems closer than ever now that the North's longtime authoritarian leader is gone.
"I'm thinking my visit home may come earlier," he said.