"He is terribly sad."
Translation:Anh ấy buồn như mất sổ gạo.
I think I know why. In 1960s, people in Vietnam have to bring a paper, that is "sổ" (giấy is paper, I know but idk why they call it sổ) , so they can have rice to eat (Vietnamese eat rice all the time). Without the paper "sổ", you wouldn't be able to have rice to eat and no rice in Vietnam, no anything else. rice is "gạo". mất is "lost".So that's why it's called "mất sổ gạo", and that is "lost rice paper". This "sổ gạo" stopped in 1980s
I talked with a native speaker who pretty much confirmed what you said. She said "sổ gao" was like a government issued, little book for the family that documented their family need for rice. This occurred after the American War in Vietnam ended, April 30, 1975. If you lost this little book, you could go hungry, thus become sad.
This information is correct (as you know this I guess you're native so no need to confirm lol)
I think most people now just don't use this idiom anymore since they don't undergo that period.
I am older and hang out with older Vietnamese. Many interesting stories about the "old days", some about incredible hardships during the war and afterwards. During my trip to Vietnam I hope to become acquainted with those that fought the Americans and hear their stories. The pieces of the "Vietnam War" puzzle are slowly coming together...
if you want to piece together the puzzle and see the whole picture, you need to have both sides of the story, meaning from those who fought against the Americans and those who fought alongside the Americans. otherwise, you'll be missing half of the pieces.