The tough training did not trouble Singaporean Jonathan Wong when he enlisted for national service in 2013, even though he was born in Papua New Guinea and has lived abroad all his life.
Making his first Singapore friends and overcoming the culture shock was harder for the 24-year-old, who looks like a Papuan, even though he attended a Chinese school and his Chinese name is Hong Jia. But he does not speak the language as he skipped Chinese classes most of the time.
But it was more than his looks that got his army mates' notice.
While his two-year stint - the second as a training officer in Pulau Tekong - was an introduction to Singapore life, it also kick-started his journey to become a national rugby player and he is set to make his SEA Games debut today against Malaysia in Petaling Jaya Stadium.
Wong's rugby skills first caught the eye of his officer-cadet course platoon-mate Max Ducourneau, a national player, when they played touch rugby together in 2014.
So Ducourneau, who won a bronze for rugby sevens at the last SEA Games, invited him to train with the national team and lent his rugby boots to his friend.
But, just like everything appeared foreign to him, it was a new ball game for Wong because he was only familiar with the rugby league code, which is played by 13-a-side teams with five tackles maximum to stop an attack, which is Papua's most popular sport.
I've never thought that I would play at this level. I wasn't aiming to go high. My goal was just to learn how to play rugby union.
JONATHAN WONG, who started off playing rugby league in Papua New Guinea.
Rugby union, played by 15-a-sides with no tackle limits, is the prevailing code in Singapore.
"I've never thought that I would play at this level. I wasn't aiming to go high. My goal was just to learn how to play rugby union," said the muscular Wong, who, at 1.75m and 77kg, is modestly built compared to other rugby players.
He returned to Singapore in late 2012 for only the second time in his life - he had last visited the Republic when he was five because his home in Rabaul was destroyed in a volcano eruption in 1994.
He recalled how people remarked if he had stolen another recruit's army uniform when he was wearing one that bore the name tag J W Hong (itself a spelling error).
"During BMT (basic military training), my friends were talking about Napfa (National Physical Fitness Award) test. I asked, what's Napfa?" he recalled.
"When Max told me he was going to play in the SEA Games, what's that? I had never heard of it."
Conversation topics were often a disconnect to him. "Why were they always talking about their studies and which university they wanted to go to?" he wondered aloud.
His time in the army also led to his nickname Papa Jon. "My section mates could never pronounce Papua correctly. I gave up."
Wong has served his NS and is currently back in Pulau Tekong as a fitness trainer drilling army recruits in physical fitness.
Singlish was a common language though, thanks to his Singaporean father Richard Wong Lian Pin, 60, a business manager who has been based in Papua for about 40 years.
He picked up the word "lepak" (Malay for relax) because it applied to idyllic activities like mountain trekking with his cousins, lying on the beach and overnight spear fishing trips.
Despite growing up overseas, he was prepared to bear arms and serve the nation. "When my brother and I were younger, my dad had a tape of the movie Army Daze and we watched it," said Wong, the fourth of five siblings - the others are 21, 25, 28 and 33.
When he runs onto the field today, his eldest sister will be among the supporters. But missing from the stands will be his No. 1 fan. His mother, July, died of tongue cancer last February at age 52.
The centre made his national debut last March at the National Stadium, scoring a try against the Barbarians and has since earned three caps.
"I want to make my mum proud. Every day when I wake up, I would whisper, good morning mum," said Wong of his mother, who used to discipline him with a tree branch.
"Mum will be there."