The death of Neil Armstrong, who died today at the age of 82, is one of those moments to think about how unimaginable his deeds once seemed. We saw this one afternoon in 1970, when we were among a clutch of reporters who followed Secretary of State Rogers on a visit to the Mekong Delta at Vietnam. Rogers was accompanied by Michael Collins, who had just become an assistant secretary of state after piloting the command module as Armstrong and Edwin “Buzz” Aldrin paced the Lunar surface.

At one point a group of Mekong Delta villagers, some of whom lived an existence closer to the age of stone than space, gathered to hear the visitors speak. Rogers himself mounted a tree stump to introduce Collins. When he tried to explain that Collins had just come from the moon, no one seemed to grasp the point. The state secretary pointed up to the silver moon, visible at the moment in a blue sky. Then gestured to Collins, as the poor villagers stood there mutely, too polite to issue catcalls of disbelief.

It was understandable enough. Since then there have been enough trips to the moon that it came to seem, however erroneously, almost prosaic. This was marked in Tom Hanks’ brilliant movie “Apollo 13,” about the voyage led by James Lovell. Of all the 12 men who’ve walked on the moon and the 12 whom Wikipedia describes as having flown within a few hundred kilometers of the moon, Armstrong seemed the greatest. Even among that extraordinary group, there was just something about Armstrong.

It might have been simply that there could only have been one person who was the first man on the moon. It was a distinction he rarely used, though he offered inspiring remarks in his address to a joint meeting of Congress shortly after he returned from the moon. He talked of how, when he got back, he took his sons to what he called the “highlands of this nation” near the Continental Divide and introduced them to “the wonders of nature, and pleasures of looking for deer and for elk.”

“In their enthusiasm for the view they frequently stumbled on the rocky trails,” he told the Congress, “but when they looked only to their footing, they did not see the elk.” He expressed his gratitude to “those of you who have advocated looking high . . . for you have granted us the opportunity to see some of the grandest views of the Creator.” Then he said: “To those of you who have been our honest critics, we also thank, for you have reminded us that we dare not forget to watch the trail…” What a remarkable man.

And yet, for more than 40 years, he fell more or less publicly silent, though he did speak up in recent years against plans to retreat from manned exploration of space. It’s possible to imagine that his modesty stemmed from an aversion to showmanship and celebrity (he once sued a barber who’d sold some of his hair). Or just to his nerdiness, the pride he took in being an engineer, or his dedication to his teaching. Or maybe to Neil Armstrong we all seemed like the Vietnamese villagers, staring at the strange man said to have been to another world that, even with all the photographs, radio messages, and moving pictures, seemed so hard to comprehend.