It was the Summer of Love, the first one. Young people were making their voices heard in politics and revealing the widening chasm between themselves and their parents’ generation. The film that summed it all up was The Graduate, released in the US in December 1967, starring Dustin Hoffman as Benjamin Braddock, a despondent 20-year-old who moves back home after finishing college, and Anne Bancroft as Mrs Robinson, the much older women who seduces him.

Half a century on, and in the wake of a pensioner-powered Brexit vote and a Corbyn-inspired youthquake, all that inter-generational drama feels fresh once more. The film that sums it all up? It’s still The Graduate, soon to be back in cinemas and just as alluring, sophisticated and as emotionally unsettling as an affair with your parents’ best friend would be.

Cinema reissues can always rely on nostalgic appeal, but there’s so much more to appreciate about The Graduate, when watched through the lens of 2017. Then, as now, the political agency of 18-25-year-olds was a hot topic. That January, Time magazine named “25 and under” as their “man of the year” and it made a big impression on Dustin Hoffman, a 29-year-old Jewish actor best known for his work on the stage. He later recalled referencing the magazine’s cover in an early conversation with The Graduate’s director, Mike Nichols. “I said: ‘Did you see this week’s Time? That’s Benjamin Braddock!’ Nichols replied: ‘You mean he’s not Jewish?’ ‘Yes, this guy is a super-Wasp. Boston Brahmin.’ And Mike said, ‘Maybe he’s Jewish inside. Why don’t you come out and audition for us?’ ”

Other actors under consideration for the lead included Warren Beatty, Steve McQueen and Robert Redford, yet Hoffman’s protestations only served to convince Nichols just how perfect he was. In retrospect, it’s impossible to disagree. Much of the film’s humour derives from Benjamin’s evident discomfort in most social situations, contrasted with the glib glamour of his parents’ cohort. The New-York-based, Los Angeles-raised, Hoffman could also readily relate to Benjamin’s experience of moving back into his parents’ home after a period of living independently. The actor had done the same when The Graduate’s low-budget shoot began in LA, but lasted only a week before moving to a hotel, at his own expense. For the debt-saddled generation-rent graduates of 2017, that often depressing “boomerang” back home is even more familiar, just without the hotel opt-out.

When Benjamin arrives at his parents’ lavish Pasadena mansion, he finds they’re throwing a party, ostensibly in his honour, though everyone present is at least twice his age. His father sits him down to ask about his future plans: “I don’t know … I want it to be …” stammers Benjamin. “To be what?” asks his exasperated father. “Different,” replies Ben. One Mr McGuire steers Benjamin outside, so he can have his full attention to say, “just one word: Plastics”. Back inside, the handshakes are firm, the ties are loud and the air is fogged with cigarette smoke. In other words, this is a crowd so thoroughly Brexit-y, not even the fact that they’re American (and the EU wouldn’t formally come into existence for another 26 years) could stop them voting to leave. You can appreciate why Benjamin would feel so ill at ease.

That may be where the sympathies of a 2017 audience end, however. Many of today’s graduates would envy the kind of laid-on opportunities that Braddock rejects. A job for life in the growth field of plastics sounds very attractive compared with low pay and zero-hour contracts. Yet whether the young are excluded from their parents’ party by economic barriers or cultural ones, there is always room for a coming-of-age film that asks: what is so good about growing up? In the age of lacklustre “adulting”, The Graduate must be even more welcome.

Back in mid-60s Hollywood, the film’s producer, Lawrence Turman, struggled to drum up interest in his project. In 1964, he spent his own money optioning the original novel of the same name by Charles Webb, and then followed two years of being turned down by every major studio in town. The grownups didn’t get it, because the grownups never do, but Turman and Nichols had enough personal affinity with the material to carry it through. Turman had initially followed his father into the garment trade before veering away from that preordained path, while Nichols had been studying medicine when he decided to try showbusiness instead. Both men were staking their professional futures on the potential of a book and both, just as Benjamin Braddock did, wanted that future “to be different”.

Once complete, The Graduate baffled early screening audiences, prompting the movie promoter Joseph E Levine to suggest a tour of college campuses to help build “word of mouth”. It worked, and by early 1968, the film was attracting crowds worthy of a Corbyn rally. Writing in US weekly the Saturday Review later that same year, the film critic Hollis Alpert recalled how “lines extended around the corner all the way down the block, much like those at the Radio City Music during holiday periods – except that the people waiting for the next showing were not family groups but mostly young people in their teens and early 20s … it was as though they all knew they were going to see something good, something made for them.”

This was the kind of success that the Hollywood establishment could not ignore, and the film received seven Academy Award nominations. Nichols went on to win best director. Today it is at No 22 on the list of highest-grossing films of all-time at the US box office, after inflation, above more traditional crowd-pleasers such as Jurassic World, Forrest Gump and The Avengers.

But if The Graduate had been just the angry cri de coeur of youth, it would have dated as fast as the Braddocks’ flock wallpaper. What is special about this film is the empathy it shows for an older generation – as personified by Mrs Robinson – even in the midst of such scathing satire. The fuss recently made over the age difference between Brigitte Macron and her husband demonstrates that we have never grown out of our salacious interest in the older woman, but we’ve never bettered the original Mrs Robinson either. She is both alluring and disgusting, predatory and pitiful and, despite her unsubtle fondness for animal prints, so much more complex than all the pornified milfs and cougars that came after.

Given that the film-makers themselves were hardly teenagers – Nichols was 35 and screenwriter Buck Henry was 36 – this sensitivity makes sense. At 35, Bancroft was only six years older than Hoffman, and eight years older than Katharine Ross, who played her daughter, Elaine. So Benjamin may have been too callow to sympathise much with a “broken-down alcoholic” Mrs Robinson, but from their thirtysomething vantage point, the film-makers could clearly see both sides.

Nichols also appreciated that it would take a veteran’s experience to be as innovative as he hoped to be with the film’s camerawork. To that end, he hired Robert Surtees, then a 60-year-old cinematographer, who had been working in Hollywood since before the invention of the talkies. “We did more things in this picture than I ever did in one film,” Surtees later wrote in an article for an industry magazine. “We would do whatever we could think of to express the mood, the emotion of the scene.”

What is that mood, that emotion? Any film that opens to the lyric “Hello darkness, my old friend,” from Simon and Garfunkel’s Sound of Silence was never going to be a knockabout comedy, yet The Graduate is both consistently funny and tragic on an oedipal scale. Like all good comedies, it ends in a wedding, and yet the tonal ambiguity continues beyond that happily-ever-after, and into a shot of the fleeing couple sat side-by-side on the back seat of the bus, their faces flickering between triumph and doubt.

Maybe how you feel about The Graduate reflects the stage you have reached in your own life when you watch it. For older viewers, it’s a reminder that you, too, were young once. For the young, it’s a reminder that you too will grow old soon enough. If ever there were a film to unite the warring generations in mutual self-pity, here it is. Again.

The Graduate is released in the UK on 23 June.