SHEFFIELD, England — All day, people line up here at an unexceptional corner of a town plaza called Barker’s Pool, sometimes a dozen or more at a time, waiting to have a photograph taken with a mailbox. This is not just any mailbox, of course. It is a mailbox that has been given a coat of gold paint.


“We live in West Yorkshire, about an hour away,” said Lisa Scranage, a 37-year-old civil servant who was with her 8-year-old son, Ryan. “We’ve come especially to see the postbox.”


While there may be little spectacular about the mailbox itself, it represents the heptathlon gold medal won by the Sheffield native Jessica Ennis, who appears in gargantuan, Mao-size posters throughout the town. The mere mention of her inspires almost giddy delight in the residents of Sheffield, a long-hard-on-its-luck northern town perhaps best known to Americans as the setting of the blue-collar striptease film “The Full Monty.”


In the words of Rachel Dempsey, the manager of the bar next to the golden mailbox, “This town’s gone mental.”


After months and months of high unemployment and stern austerity, crooked bankers and shady journalists, and the hangover of riots that set parts of London on fire, the idea of a national revel seemed almost laughable, even more preposterous than revelry would usually seem in this land of sang-froid. Among those whom Mayor Boris Johnson of London calls “the Olympo-skeptics and gloomadon poppers,” it was almost a sport in itself to point out every budget overrun and logistical hiccup as evidence of the disaster that would naturally follow on such an earnest enterprise as the Olympic Games.


Even after the opening ceremony, which surprised many for being properly spectacular and deeply, ironically and absurdly British, there were still expectations of a debacle, with incompetent security officials, traffic snarls, apocalyptic downpours, corporate bloat and an embarrassingly low berth in the medal table. Many of those outside London considered the Games a local phenomenon, and a wasteful one at that.


And yet as the Games come to a close, here in Sheffield as well as all over Britain, a patriotic delirium has descended.


“The attitude was, ‘It has nothing to do with us up here,’ ” said Martyn Boardman, a consultant in town on business who with his phone had just snapped a photograph of the mailbox, one of more than two dozen around the country that were painted gold in honor of hometown Olympic champions. “But then one or two medals, and all of a sudden, we’re at fever pitch.”


The perk-up began with the opening ceremony but took hold on Aug. 1, when the cyclist Bradley Wiggins, the first Briton to win the Tour de France, became the only rider to have won the Tour and an Olympic gold medal in the same year.


“Whatever happens from here,” a columnist for The Daily Mail wrote, “it will be hard to top this.”


But the golds continued: seven more in cycling, four in rowing, three in equestrian. There have been British golds won in the cathedrals of English sport, like Andy Murray’s tennis victory at Wimbledon, and in events that most people would be hard-pressed to define, like men’s keirin. The Duke and Duchess of Cambridge have been seen at events displaying get-a-room levels of affection, and articles have appeared in the news media exploring why the British had not won gold medals in a given event rather than the more characteristic converse.


But what had been a balmy Olympic fever became a roiling epidemic on Aug. 4, when the British had their greatest night of track success ever, with a gold in the long jump, Britain’s first gold in the 10,000 meters and Ennis’s golden smile coming across the finish line in the final event of the heptathlon. With that, the whole of Britain seemed nearly to come unglued.


“I’ve been in the Millennium Stadium when Wales have clinched a last-gasp win against England in the Six Nations,” wrote a sports reporter for The Western Mail, a Welsh paper, describing a rugby triumph, “but I have never heard such a noise as that which erupted on Saturday.”


This is saying something indeed. While England’s St. George’s cross, Wales’s red dragon and the Scottish saltire are all common sights in soccer season, as the kingdom un-unites in rooting partisanship, a Union Jack is typically a rare find.