The father is the longest-serving staff member in the Republic of Singapore Air Force (RSAF). The son worked as a medical officer in the RSAF. Neither knew, as young men, how meaningful they would find the experience.
Fate, and Mr Lee Kuan Yew, intervened.
Back in 1967, 19-year-old Prasad Kumar Menon had set his sights on getting a law degree at the University of Singapore, when the British announced they were withdrawing their military presence from Singapore by 1971.
Mr Lee and his team decided the Republic should protect itself with its own resources. An air force had to be built from scratch.
Mr Menon signed up as a trainee pilot but ended up as an air traffic controller. "I felt it was my duty at a time when my country needed me to do the right thing," he said.
When he stopped at 52, he was immediately engaged as a consultant in the RSAF's air operations department. Today, he is the RSAF's longest-serving staff member.
He said the way in which the RSAF has soared bore testament to the spirit which Mr Lee invoked in a 1967 parliamentary speech, asking Singaporeans to "adapt and to adjust, without any whimpering or wringing of hands" when British forces withdrew.
Mr Menon said: "Being forced to start from scratch, and think out of the box so early on, made us mature very quickly."
Interestingly, when his son Raj Kumar was growing up, he did not take national service seriously at first.
"It's something you just had to do - become fit, to be garang (Malay for tough), like what you see in the Ah Boys to Men films," said the 34-year-old, who went through basic military training in 2000, before interrupting his NS stint to go to medical school.
Reality hit when he returned to the RSAF to serve as a medical officer in 2006.
He helped evacuate servicemen who were hurt in a fighter jet crash in Taiwan in 2007.
Two died at the site, while another died from severe burns 17 days later in Singapore.
Recalling the 20-minute journey to the hospital in an ambulance with one of the burn victims airlifted back to Singapore, Mr Raj said: "All the drills, the equipment checks, things that we used to do in the medical centre and training, were suddenly very real.
"In front of you was someone who had made a big sacrifice while serving the nation. You wanted to do your best to bring him home.''
Mr Raj is now a registrar at National University Hospital's general surgery department. But he often mentors junior SAF medical officers and medics.
He said: "NS is not lip-service. You believe in your mission because you realise that this is not for show. This is essential.''