I found this film to be something of the darker flip side of American Graffiti. Where George Lucas' love letter to 50s Americana was about hope and optimism for the future of adulthood no matter how uncertain, The Last Picture Show is about the end of things, the death of people, the end of innocence and the revelation that the squeaky-clean varnish America saw itself through in the 1950s was just a façade hiding alcoholism, marital discord, boredom and loneliness.

Bogdanovich goes for a naturalistic rather than a stylised approach in the story of Sonny (Bottoms), Duane (bridges) and their friends, contemporaries and seniors. The good-natured town patriarch Tom (Johnson) holds everything and everyone together as the owner of the diner – run by the sardonic waitress who's half mother, half lover to the boys – and the movie theatre where a generation of kids go to make out and feel each other up. He's even as forgiving as he is firm when the gang terrorise his mentally ill son by taking him to an abusive hooker to pop his cherry.

But with Tom unexpectedly out of the picture, everyone's problems seem to turn worse. Duane's girlfriend Jacy (Shepherd) is far less interested in being his smalltown girlfriend than she is at tasting life, even at her bored mother's (Burstyn) urging. Duane, wracked with anger and heartache, leaves, firstly to work out in the desert and then off to the Korean war.

And Sonny, who's been seeing lonely housewife Ruth (Leachman) in an affair that's as tender and halting as it is sad and beautiful, falls under Jacy's scheming charms and ends up hurting everyone in the process.

Jacy comes across somewhat as the antagonist of the tale, completely prepared to shamelessly play the boys off against each other to get what she wants, knowing full well how sexually irresistible she is. In a way everyone from Duane to Sonny are left twirling in her wake.

It's as approachable as it is enigmatic, and despite the reputation that preceded it, all I knew was how beloved it was. I expected something stagey and not very genuine, but it was raw and frank with everything from sex as a cure for boredom to heartbreak.

Every era has a classic American movie that parallels a decline – of the economy, of the rural sector, even of Hollywood itself – that's often copied but seldom bettered. Just have a look how similar the first and last shots are to Paul Schrader's recent The Canyons. A sense of hopelessness and inevitable loss pervades The Last Picture Show throughout, giving it the deathly pallor of a zombie movie (where you know you can only run so far because they're going to catch up with you eventually), but it's compelling and watchable.