I am about to commit a grave sin; that of reading somebody else's diary – one written by a 13-year-old boy. I carefully open the volume, penned by one Godfrey Williams, and am confronted by a stark warning on the inner leaf to any potential snoopers: "Take note: all persons who look at this diary without my leave are Beastly Sneaks."
The author hasn't exactly given me his express permission to leaf through his journal; I hesitate, but only for a moment, before turning the page, Beastly Sneak that I am. Williams began writing his diary at boarding school when he was eight years old; that was in 1881. The volume I'm looking at is one of the 76 he filled up during the course of his life.
I have been granted access to an array of personal journals, including Williams's, by the self-styled "diary rescuer" Dr Irving Finkel.
He has a job title that sounds as though it's been conjured up by J K Rowling – assistant keeper of Ancient Mesopotamian script, languages and cultures in the department of the Middle East at the British Museum – and is an expert at decoding cuneiform inscriptions, the oldest known form of writing. He is also a diary fanatic on a crusade to seek out and safeguard the tomes of ordinary people.
Upon meeting Dr Finkel I am thrilled to discover that not only does he sound like a character from Harry Potter, he looks like one, too; with his long, white beard, tall, thin frame and little, round spectacles, he bears an uncanny resemblance to Albus Dumbledore.
Every diary, he tells me, is a valuable resource full of remarkable details. "All human life is there, and every entry is helpfully dated for future historians," he says. What might seem today to be banal and unimportant will, over time, take on a huge significance.
Yet most diarists make no provision for what should happen to their journals after their own demise; those who inherit them often dispose of them unthinkingly or destroy them with the good intention of warding off prying eyes.
Desperate to ensure their survival, Dr Finkel has launched The Great Diary Project, a permanent archive to which members of the public can donate unwanted diaries. Here they will be preserved and catalogued on a database available for researchers and interested readers to peruse.
"How marvellous it would be if people a long time in the future could read about people's daily lives and realise that people in our time were like them, as we, if we had diaries from the 15th century, would know people 600 years ago were like us; they cared about the same things," Dr Finkel says.
Dr Finkel has dreamt of creating a repository for the diaries of ordinary people ever since he came into the possession of Godfrey Williams's long run of journals some 15 years ago, when a friend of his had tried to sell them to the Imperial War Museum. After completing school, Williams had become a soldier; the museum only wanted the sections covering the war years and had no interest in anything else.
"As far as they were concerned, he could chuck the rest away," Dr Finkel says, shaking his head in disbelief. "This was one man's life from school to a very old age. It seemed tragic to me that there was such an attitude that only a portion of this archive was worth rescuing."
Dr Finkel bought the whole lot on a whim – "It really was a corker," he says – and never looked back. Now he is finally on the verge of seeing his dream become a reality. In 2012, he took to the airwaves in a bid to drum up donations to his growing archive.
Hundreds of listeners were moved to contribute their diaries to the cause following his appeal on Radio 4, and the project snowballed. The initiative even attracted the attention of Stephen Fry and Boris Johnson, both of whom serve as patrons of the project.
Dr Finkel's office at the British Library is now crammed full of journals – he had collected more than 2,000 at the last count. Fortunately, for the sake of his colleagues, he was approached by fellow diary zealot Stefan Dickers, the library and archives manager of London's Bishopsgate Institute, where the collection he and Dr Finkel have amassed is soon to be officially housed.
"When I heard about this project I was so excited I couldn't sleep," Dickers tells me. "I'm a complete diaroid!" says, guffawing.
Dr Finkel, Dickers and their dedicated team of "diaroids" are now preparing to showcase a selection of diaries in a new exhibition. Featuring personal accounts from children and young people dating from 1813 to 1996, it will open next week at the V&A Museum of Childhood in London, where it will run until October.
There is plenty of humour to be found between the covers of the exhibits: in one 1927 book, on the page encouraging diarists to list the "Entertainments I have been to", the eight-year-old writer loftily declares in enormous black lettering: "I do not go to such things. I am a religious minister's daughter."
There are countless tragedies, too, some minor – such as the cruel rejection of a teenager in the 1990s by her best friend, who moves to sit next to another girl in history class, leaving her "utterly alone" – and some more grave.
Schoolboy Raleigh Trevelyan recounts tales of bedbugs and flogging in his 1813 diary, with sporadic references to the Napoleonic Wars interspersed among descriptions of the weather (mostly rainy) and the writer's dinner (mostly new potatoes).
When he suddenly gets ill he describes the terrible headaches and nosebleeds he suffers from; there are actually droplets of his dried blood splattered on the diary's pages. He is given a rhubarb drink to revive him and leeches are put on his temples but to no avail. Trevelyan died aged 13.
While Trevelyan never progressed into adulthood, the diaries of those who did often reflect the process of moving away from childhood, says Laura Barnicoat, curator of the exhibition. "The diaries serve as a space for them to start developing their ideas and initiate them into a more adult realm," she adds.
Take the five-year journal written by Joan Hall. Starting in 1937, a few weeks before her 15th birthday, the diarist documents in great depth – and minute handwriting – her endeavours to select an appropriate husband.
She is particularly taken with a boy she refers to only as "Glasses", whom she pursues around London, industriously logging every sighting. She briefly mentions seeing Laurence Olivier perform in Macbeth at the Old Vic but is too consumed with passion for Glasses, whom she spots at the bus stop, to discuss this landmark event in any detail.
On Armistice Day that year, Hall reports that it is her friend Joyce's birthday. She has bought her an offbeat gift: a novelty coat hanger. In the next sentence her thoughts flit momentarily to the Second Sino-Chinese War raging between Japan and China, and she briefly laments "the poor people who are dying now, at this minute, in China. It is cruel." However, upon spotting Glasses at the dinner table her spirits are buoyed.
Hall's tendency to bypass major world events in order to relay seemingly trivial affairs is not unusual. Indeed, it is a characteristic common to diaries written by people of all ages and backgrounds.
Dr Finkel tells me that many of the diaries he has from the Second World War barely allude to the momentous events the writers were living through, with diarists noting down instead the price of bread and when they planned to wash their hair.
Personal diaries reflect ordinary people's experiences and the everyday issues that interest or trouble the writers. They are written unselfconsciously, without an agenda, unlike those belonging to politicians and admirals, who all too often use their journals to "spin" history.
"Who else but me is ever going to read these letters?" wrote one of the most famous diarists of all, Anne Frank.
Hall's diary acts as a receptacle for all her secret thoughts as she tries to work out who she is meant to be with. As the reader, you're rooting for her mysterious bespectacled paramour throughout, so when, aged 19, she meets an American soldier and decides to settle down with him instead, you feel almost robbed.
Hall then ceases to write. Her last entry explains in quite poetic and melodramatic terms that now she has decided to commit to one man, she has elected to stop writing her diary. The remainder of the pages are left blank.
"There's a lot of sadness when a diary ends because often you don't find out what happens next," Dr Finkel laments.
Sometimes, though, he does learn what becomes of the diarist as a significant proportion of The Great Diary Project archive is comprised of contributions from living donors.
Like Hall, Veronica Hadwyn, a teenager living in Cornwall in the 1940s, chronicled all her romantic encounters in her diary. On 23 May 1947, when she is holidaying in Dublin, she describes her crush on an older man who – despite suffering from tuberculosis – is quite devastating.
"Today I met the famous Finton Halpin – and fell for him," the 17-year-old writes. "He has TB and only has one rib, consequently his shoulders are crooked – but his charm and his handsomeness make up for it and more – he has yellow eyes and high cheekbones – in fact is rather a dream."
Fast-forward 67 years and Hadwyn – now Veronica Chalmers – is living in Bristol. Aged 84, she has three adult children and six grandchildren. She lets out a hoot of laughter when I mention Finton and confesses that her feelings for him sadly weren't reciprocated.
Chalmers happily handed over her diary to Dr Finkel and is unperturbed at the prospect of her innermost thoughts being put in the public domain: "When you get to my age you don't care," she says.
"I remember my past more clearly than last week," she adds, "But I don't really feel I know that girl any more."
Nevertheless, the fact that she held on to the diary for all those decades before surrendering it to Dr Finkel's guardianship to be conserved for future generations suggests a desire to keep alive the memory of the girl she claims to no longer know.
Dr Finkel believes this could actually be the reason so many of us choose to write a diary in the first place: because, subconsciously, we hope that eventually somebody, somewhere, will read it. He concedes that his theory sounds counterintuitive: "Many people would rather die than have somebody else read their diary," he says.
But, he insists, while the idea of a partner, child or even grandchild reading one's diary may be mortifying, the passage of time changes things. "By the time 100 years has passed, the privacy element is a bit daft," he says.
In that case, will Dr Finkel be bequeathing his own diary to the project for Beastly Sneaks of the future to scrutinise at their leisure? "Oh no, I don't keep a diary," the electric-bass-playing scholar of Babylonian exorcistic spells replies breezily. "No normal person ever admits to that."µ
The Great Diary Project; 17 May-12 October 2014, V&A Museum of Childhood, Admission free; museumofchildhood.org.uk