Rubes in the city — think of Gary Cooper’s Mr. Deeds or the beaming, North Pole-raised simpleton Will Ferrell played in “Elf” — are reliable film subjects because their wide-eyed amazement makes the modern environment with which the rest of us are familiar, even bored, seem new. If the unabashed awe these characters display doesn’t rub off, it might make you think — or, at the very least, chuckle. The documentary “God Grew Tired of Us,” which belongs to the same tradition, manages to do all three. More to its credit, this uplifting study of four Sudanese refugees in America stirs wonder in the viewer too: The heart and perseverance of woe-begotten young immigrants comes across, at points, as nothing short of miraculous.

It’s a trait shared, of course, by many true stories of this sort. But the 2003 documentary “Lost Boys of Sudan” explored a nearly identical scenario — and even featured the same refugee camp in Kakuma, Kenya — with strikingly dissimilar results. That film, which profiled a different group of Lost Boys (as they became popularly known, from the band of orphans in “Peter Pan”) selected for the International Rescue Committee’s American resettlement program who fled the same civil war, was not about triumph; it was about their struggle to adapt to life in America. They were repeatedly robbed, and many of them failed to make friends or hold a steady job. Worse, they quickly became cynical about the land of plenty. “Back in Kakuma, we thought America was so great,” one of them said. “But now it’s clear, there is no heaven on earth.”

The young men in “God Grew Tired of Us” maintain a more positive outlook. (Incidentally, they also weren’t assigned to live in Houston.) Having endured the horrors of the war — which they enumerate, along with narrator Nicole Kidman — and languished for 10 years in a refugee camp, they greet the news that they are being transferred to America with the same eager determination that sustains them later on through the mounting frustration of being away from friends and family.

Lifelong village dwellers, they are fueled by an intense curiosity from the get-go. One of them says he doesn’t know what an apartment is but is eager to find out; another wonders aloud whether New Yorkers commune at a river to bathe. Their first encounter with Western cuisine takes place on an airplane, but even that doesn’t crush their spirits. And while they may seem timid and withdrawn upon their arrival in Syracuse, New York, they are in fact soon desperate to know more about their new home. One of the film’s most memorable comments comes from a gentle giant of a man named John. He says he and the other Lost Boys have many questions about America, but no one to answer them.

Indeed, what proves more difficult than the long work hours (John packs gaskets at a factory, then works a shift at McDonald’s) or the unfamiliar credo that “time is money,” is a society in which people are left so completely to their own devices. They are loaned money, and a refugee program officer comes by to demonstrate to the newcomers how the toilet and light switches work; after that, their lives are pretty much up to them. Whether this constitutes independence or abandonment is a question the film doesn’t pursue; it is, however, certainly one reason for the refugees to stay close to Sudan. John refuses to eat with utensils; Panther, the most financially successful (and, it appears, Americanized) of the group, dreams of returning there to marry his sweetheart and build a school.

The film quietly sidelines the characters who don’t flourish in America; for this reason it is perhaps best viewed alongside “The Lost Boys of Sudan,” and balanced out by that film’s less rosy view of the immigrant experience. But “God Grew Tired of Us” tells a straightforward and inspiring true story. John is clearly the favorite subject of co-directors Christopher Dillon Quinn and Tommy Walker, and he holds the film on his shoulders. He has a thick brow, an enormous frame, and wide-set eyes. His imperfect English sounds at times like poetry. “I’m now again wearing clothes and feeling happy,” he announces on a perfectly average day in Syracuse. Who would guess that this man wandering outside a Wal-Mart parking lot once led 1,000 starving boys across the desert, feeding the weak ones and burying them when they died?

Moreover, who would guess the reason he gives the filmmakers for doing it? “God does not create me as a very tall person for nothing.” In those unscripted words lies the surprise of a rare and wonderful sentiment.