[moonrab]

We can be proud of it...which is a far cry from the early days when parents were unhappy about their sons being conscripted.

Outside of Singapore, who gives a shit if you say "I did NS"? Don't expect foreigners to be proud of us and say wow! Singaporean men did NS wor! Wow! Wow! Wow! 

So I wonder why he kept repeating that he did NS?

When someone or a foreign entity claimed you are not a Singaporean or belongs to another foreign government's interest. 

It is logical to state you served Singapore NS as a official referendum to your position in Nationalism. 
NS is the core of all male Singaporean's share common interest in life. 

It doesn't matter what foreigners view about it.