Being enlisted for national service at 26 was not easy for Mr Mark Adam Collins.
Now 33, he had moved to Australia when he was nine.
Mr Collins, who speaks with a slight Australian accent, says: "I grew up in Australia and always thought of myself as Australian." But this changed at 25 when he arrived in Singapore to work as a part-time English language trainer.
Under the impression that Mr Collins is an Australian, his employer applied for a work permit for him - only to be told that it was not required.
Mr Collins is a Singaporean.
A week later, he received a letter informing him to report for a medical check-up and enlist for NS.
He recounts: "I was so shocked at first, and I thought I was too old. But I wasn't going to run away. I decided to just do it."
Instead of classrooms, Mr Collins found himself marching on the parade square in his Singapore Civil Defence Force (SCDF) uniform. He eventually trained to be a fireman section commander.
The stark change in lifestyle hit him hard at first.
"While people my age were building their careers or getting married, I had to wear a uniform for the next two years," he recalls. It was a stressful period for him.
Mr Collins admits there were moments when he felt depressed over the situation. He is able to look back with a laugh now. "I kept getting scolded for not knowing the commands in Malay. But how was I supposed to know?"
Despite the rocky start, NS turned out to be the best time of Mr Collins' life. His training later led to working alongside his mates at Bishan Fire Station and that allowed him to forge bonds that Mr Collins says are "irreplaceable".
He remains close to many of his NS friends and they still meet up.
Being in the SCDF also invoked a sense of purpose in Mr Collins. He realised he likes "helping people".
That "discovery" inspired him to become a senior officer in the Airport Emergency Service, where he attends to emergency situations like fire and accident at Seletar Airport.
He says: "It didn't matter what age I went, I am glad I did NS eventually because it got me to where I am today."
The case of Melvyn Tan
Singapore-born pianist Melvyn Tan moved abroad when he was just 12 to study music in the UK.
By the time he returned in 2005, he was 49. As such, he did not do his national service.
He was fined $3,000 for defaulting on his NS. Under the then-Enlistment Act, he could have been fined up to $5,000 or jailed up to three years, or both.
The case of Brandon Smith
He was born here but Mr Brandon Smith, 19, moved to New Zealand when he was eight.
He is now seeking an exemption from national service, reported news website stuff.co.nz.
Mr Smith, who lives in the city of Dunedin, was reportedly called up for a pre-enlistment medical screening here.
In the article, Mr Smith was quoted as saying that spending two years in NS was "difficult and pointless".
He also said that the allowance would not be enough, and that his inability to speak Mandarin would cause him to be treated as an "outsider" during NS.
Mr Smith's multiple attempts at deferring his NS call-up until the age of 21 had allegedly been rejected, even though his younger brother was granted a deferment.
His father, Mr Shane Smith, is a New Zealander and has served in New Zealand's air force.
In a bid to help his son avoid NS, the senior Mr Smith has been in contact with authorities in Singapore for years, stuff.co.nz reported. The senior Mr Smith said: "Absolutely no one would accommodate us. It was always the same answer, 'We regret to inform you that Brandon has to serve national service.'"
He added: "Obviously, for Brandon, it's not what we want. If he doesn't go back to Singapore to serve his NS, then he can never enter Singapore because he runs the risk of being arrested."
The New Paper on Sunday spoke to other returning Singaporeans who have served NS.
After living in Australia for most of his life, Mr Mark Adam Collins served his NS only at 26. He feels that Mr Smith is denying himself a great opportunity.
"While I understand his concerns, he should just go for it," the 33-year-old says.
"Friends I made in NS became brothers. To be honest, it was one of the happiest times in my life. I would go back to that period in a heartbeat."
Mr Aneirin Flynn, who moved here from England after he received the letter to serve NS, empathises with Mr Smith, saying it is a "difficult situation".
Mr Flynn, 22, says Mr Smith is entitled to his decision to not serve NS but believes it would be "his loss" if he decides not to.
Mr Flynn says: "NS can be a positive transformative experience, and he will undoubtedly make good friends and share some unforgettable memories."
Brother taught him to prepare
When Mr Samuel Mirpuri, 20, returned to Singapore to serve his national service, he had only three days of preparation before his enlistment on Dec 9, 2014.
Mr Mirpuri, who has about 10 months left to serve, says: "I had only a short time to prepare and psych myself up for this huge thing." Luckily, Mr Mirpuri, who was born and raised in Spain (his father is Spanish and his mother is Singaporean), got some useful advice.
His elder brother, who enlisted just eight months before him, quelled some of Mr Mirpuri's fears by telling him what to expect.
"My brother thought me a few tricks, like how to tie my boots and the importance of prickly heat powder," he says.
"He even taught me some Malay commands."
Mr Mirpuri's brother also advised him to train physically to prepare for the rigorous demands of NS.
He started exercising more and went jogging to train for the 2.4km run component of the Individual Physical Proficiency Test.
But all the tricks his brother taught him did not prepare him for the jet lag and difference in temperature he would experience.
Mr Mirpuri says: "Since I came back only a few days before, I was not fully adjusted to life here."
Not only did he have to adapt to the local conditions, he also found himself confused about local slang.
Mr Mirpuri says that whenever he heard an unfamiliar Singlish term or a Hokkien expression, he would check with his fellow recruits. His friends in Spain are starting university, but this does not bother Mr Mirpuri. He feels that he is being educated in "a different kind of school".
"They might be learning things from books, but I am learning about different things like leadership and how to manage people," he says.
Mr Mirpuri's performance in this "different kind of school" has been stellar.
He recently graduated from Officer Cadet School and received the Sword of Honour, an award given only to the top cadets. He is now serving as a platoon commander in the armour vocation.
Mr Mirpuri's time in NS has even made him fall in love with the country.
When asked if he would defend Singapore should the need arise, he answers with a resounding "yes".
While he has not decided on his post-NS plans, Mr Mirpuri says he is considering studying renaissance engineering at Nanyang Technological University.
"There is so much to love about Singapore. The food, the people, why wouldn't I want to come back here again?" he says.
This article was first published on Jan 31, 2016. Get The New Paper for more stories.