The more he hears of North Korea's missile and nuclear tests, the more anxious Mr Samuel Kim, 37, feels.
"If North Korea continues to conduct missile and nuclear tests successfully, it will become a very serious threat... Most of us hope that war will not break out," said the gaming company employee yesterday, a day after Pyongyang conducted its sixth and most powerful nuclear test to date.
Advertising executive Ji Yeon, 27, was less affected. "When we see the news, we'd just say, 'Damn North Korea', and that's it. Most people don't think we're in danger."
South Koreans have had mixed reactions to the latest nuclear test - some are worried, some blase, and others, simply resigned.
Even as calls grow in the media and opposition circles for the government to develop its own nuclear weapons to counter the North, in case the United States pulls out of the alliance, there is also a sense that there is nothing much South Korea can do.
President Moon Jae In's administration has insisted that it wants to be in the driver's seat over North Korea, but its numerous offers for dialogue have all been snubbed.
What's worse, South Korea is now under pressure from the US to renegotiate their 2012 free trade pact.
US President Donald Trump has threatened to withdraw the "horrible" deal, which he claims led to the US trade deficit with South Korea to double to US$27.6 billion last year.
Last Saturday, he said he was thinking of pulling out of the five-year bilateral agreement - after trade officials from both sides met last month but failed to reach an agreement about renegotiating the deal.
Some analysts have warned that nullifying the deal now could send the wrong message to North Korea that the US-South Korea alliance is shaky, while others said it could be just a negotiation tactic to exert more pressure on South Korea.
South Korea's Trade Ministry said on Sunday that it is preparing for "all possibilities".
Political commentator David Lee told The Straits Times that South Korea may have to give in eventually, as "security is much more important than the economy".
He said: "Without the US nuclear umbrella protecting us, South Korea's economy will crumble."
For the average South Korean in the street, uncertainties over the North have led to more worries.
Ms Chloe Lee, 40, who works in an IT company, said her friends have been talking about North Korea's nuclear test on Sunday.
One friend even started stocking up on food a few months ago when the threat became more severe, she added. "Some people are worried, some are not. But it seems there is not much that we or other neighbours can do (to stop North Korea).
"We're worried but we know there are no solutions, so we become even more worried."
Mr Lee said: "South Korean people believe we are in a miserable position. We can't develop nuclear weapons, nor can we decide on policies independently. We always have to follow the US. We want to get out of the situation, but our hands are tied."