It is not hard to see why it was done, and it is hardly a huge change in any event, but it bothers me all the same.

With the centenary of the First World War coming to a close on Armistice Day this Sunday, there has been a great deal of excitement about Peter Jackson - director of the two, three-movie epic journeys through J R R Tolkien’s Middle-earth - and his latest piece of film wizardry, in which footage of soldiers on the Western Front has been tidied up, colourised and provided with a soundtrack based on lip-reading and the archives of the Imperial War Museum.

The film is, obviously, a highly polished piece displaying great technical skill, and the dislocation of seeing century-old footage rendered in as high a quality as you might achieve on your iPhone today is stark. As Jackson promises, it does provide a new way to look at the past.

But the small change that bothers me is in its title: They Shall Not Grow Old. Almost anyone with a passing knowledge of the Great War will recognise that this as an allusion to war poetry - if you know nothing else about the war, it’s odds-on you will be aware that it inspired a great deal of verse. People may recognise the poem that the line is from, even if they do not know its name or its author - For the Fallen by Laurence Binyon. The particular stanza that the line is from is sometimes known separately as the “Ode to the Fallen” or the “Ode of Remembrance”.

But the problem is, Jackson’s title is wrong. The stanza runs: “They shall grow not old, as we that are left grow old: / Age shall not weary them, nor the years condemn. / At the going down of the sun and in the morning / We will remember them.”

“They shall grow not old”, an archaic reframing of the expected word order, is how the poet wrote the line, but Jackson has changed it to sound more regular to the modern ear.

No doubt there are sound reasons for doing this - perhaps, in an age of social media commentary about everything, he simply didn’t want to have to spend hours on Twitter pointing out to armies of smug trolls that, no, it was they who were wrong and, actually, it’s a quote from a war poet.

But it still bothers me, because it feels like an example of a constant niggle I have had throughout these centenary years: that, while we have endlessly avowed that “we will remember them”, the actual voices of the men and women who fought through and endured the First World War have been edited to suit the sensibilities of the modern audience.

In Alan Bennett’s The History Boys, the charming Irwin - summoned to tutor a group of boys not in history itself but in manipulating it to sound cleverer than their peers in Oxbridge interviews - opines that “there is no better way of forgetting something than by commemorating it”. He, too, is talking about the First World War. As a proxy for Bennett’s own reading of the past, Irwin is implying that the memorials found in every town and village across the country went up only to hide the culpability of the British elite in starting the war; a view at odds with substantial amounts of modern historical scholarship.

But the neat phrase does capture much of what has happened in Britain’s centenary celebrations - the deep learning across the nation that should have flowed from the intense focus on the war over the past four years has been occluded by a fixation on gaudy spectacle and trite moral instruction.

A cause worth fighting for?

Witness the Westminster Abbey service commemorating the outbreak of the war, in which the causes and course of the conflict were described in terms akin to a natural disaster: vast, impersonal, perhaps unavoidable, but certainly no one’s fault. The compelling reasons why men volunteered in their millions - whatever we might think of their views today - were absent. Instead, it was a terrible thing that happened and all those who fought were victims; this despite the vast accumulation of material in which many soldiers, and their loved ones at home, affirmed their conviction that the war was worth fighting, during and after the conflict.

Historical experts who might have been able to reflect such complexity, and explain why people who fought could feel so differently about a war now regarded in the popular memory as futile, were sidelined - quite literally in the case of one of the BBC’s flagship centenary programmes, which gave Niall Ferguson a vast stage to communicate his message that Britain ought to have stayed out, while a dozen other historians, all with a longer pedigree researching the war than Ferguson, were squashed into a corner of the studio to offer their reflections only when called upon.

The BBC spent much of 2014 trumpeting its commitment to engaging with the centenary, and even had a “centenary controller” leading its whole offer. But no new epic documentary was commissioned to explore and explain the totality of the war for a modern audience. It is true that 1964’s The Great War was reshown, but it is no longer available on the BBC’s iPlayer service, despite the centenary not yet having finished. Other, less comprehensive documentaries were commissioned, mostly involving celebrities rather than historians, and much of the most demanding content was for radio, not television.

In the wider cultural sphere, some grandiose art was created, most memorably Blood Swept Lands and Seas of Red, which filled the moat of the Tower of London with more than 800,000 ceramic poppies: one for each of the fallen British and Commonwealth soldiers of the war. The success of the installation as public art was clear - some 5 million people came to see it - but, by its nature, the piece drew attention to the dead en masse; there was no scope for the dead to speak individually of the diverse reasons why they chose to fight. And, as with so much in these centenary years, those who survived the conflict and lived in the world the war helped to create were afforded no voice at all.

This all matters because the First World War is not something anyone teaching history in this country can ignore. The fanfare around the centenary was not misplaced: the war is the catalyst of the modern world. To take one example, it birthed fascism and Leninism, ideologies that, in another world war and the Cold War, would contest with the liberal democratic idealism associated with America’s leader during the 1914-18 conflict, Woodrow Wilson. Social, economic, cultural and religious systems were forged anew in the First World War, and their effects live on palpably today.

So, the war must be taught. But teachers alone in their classrooms do not have the time nor the resources to contend with popular but discredited ideas, such as the one embodied by the phrase “lions led by donkeys”. No serious historian accepts the view that Britain’s generals were heedless butchers, although academics vary in their degree of praise for those generals. But teachers contesting this view in their classroom will be doing so against a wall of popular imagination about the leadership of the conflict that the centenary has done little to pierce.

Whether it is Wilfred Owen’s ironic Dulce et Decorum Est, Joan Littlewood’s anarchic Oh, What a Lovely War!, or the sudden switch from comedy to tragedy in the closing moments of Blackadder Goes Forth, influential cultural touchstones for the absurdity of the war abound. Teachers may work against this trend in pursuit of a more valid and complex understanding of the past, but they cannot overcome it alone. It is a great shame that nothing has been made - by artists, politicians or broadcasters - over the past four years that can match this enduring power over the public imagination, and challenge such ideas on the basis of the far wider and deeper historical research that ought to enrich our understanding of this extraordinary, century-old conflict.

It’s not that I hope schools will avoid Jackson’s They Shall Not Grow Old - for a start, the film is obviously more deeply grounded in the realities of those men whose conversations and memories it captures than other centenary artefacts, and no doubt history teachers will skilfully deploy it.

I just wish, after all the money and time and effort put into the centenary, we as a country had more to show for it, and teachers had more to use from it, that would serve to remember those who died and survived as they were, and not as we might want them to be.

John Blake is an experienced teacher, education writer and policy researcher