I came to One Day a little late. It was published in 2009, but I did not read it until some time early in 2010. I knew a little about its author, David Nicholls, of course: I'd seen the films When Did You Last See Your Father? and Starter for 10, whose screenplays he had written, and his heavenly adaptation of Thomas Hardy's Tess of the d'Urbervilles on television. But I had not read either of his other novels, and this one, with its bright orange cover and its shouty jacket quote by Tony Parsons, I found – who knows why? – eminently resistible.
Then, one evening, a girlfriend whose literary taste I've never had cause to doubt, told me to try it. "Honestly," she said. "It's a Ronseal book. It absolutely does what it says on the tin. It's completely satisfying and lovely." Soon after this, I made my own contribution to the novel's amazing success – more than a million copies sold in the UK so far – and 435 pages later, I, too, had become another evangelist for it. I told everyone I knew to read it, and those who did, I noticed, always thanked me afterwards extra-enthusiastically, as if I'd let them in on some extraordinary secret. My husband read it, too, and while he was doing so, I caught him quietly blubbing in bed. Which was weird because he is emphatically not a blubber.
By this time, the book was everywhere (if, for some inexplicable reason, you haven't read it, it tells the story of Emma and Dexter, who meet at university on St Swithin's Day, 1988; it then revisits them on the same day for the next 20 years). Its traffic-cone jacket flashed at me from Tube and train and bus. I grasped that it was a word-of-mouth hit, and a big one at that. But I don't think I realised how big, exactly, until the morning last January when a highly distinguished 96-year photographer whose house I was visiting (long story) asked me, in the course of making small-talk, if I had by any chance read it. I told him that I had. He grinned. "It's good, isn't it?" he said, nodding vigorously. "I mean, it's really very enjoyable."
And so it goes on. Nicholls and I meet in a restaurant near his home in north London and sure enough, about halfway through our conversation, a woman appears at our table and tells him that, only last night, outside the theatre across the street, she finished his novel. "It was beautiful," she says, the adjective rather at odds with her straightforward tone. Nicholls thanks her. "That's very kind," he says. Unlike certain authors of my acquaintance, however, who accept praise in much the same way that Queen accepts flowers (graciously, but without any hint of surprise), you can tell that Nicholls means it. He is, he says, still so very grateful. "I'm grateful that I found a job I could do, and that I love, and I'm grateful for the success of the book, and I suppose I think that because I've been so lucky, there's an obligation to try to be sensible and decent about the whole thing." He emits the tiniest agonised sigh. "But it's so stupid. Because, of course, [success] also makes me anxious, paranoid, guilty... all of those things."
Why? "Well, it's so hard for books to take off. You give years of your life to something that probably won't happen, so when it does, it feels a little... unjust." Is he worried his success will unaccountably come to a sudden stop? "Not a stop, no, but the idea of keeping going for another 20 years makes me a little panicky, and [then there is] the prospect of a backlash, or the next book not being so good or doing so well. None of this is a complaint. It would be churlish to complain. As a novelist, I'm incredibly lucky to make a living, but that doesn't mean that I don't lie awake at four o'clock in the morning, worrying. You have incredible ups and downs. Most of the scripts I've written haven't done great box office; Starter for 10 did OK, but The Understudy [his second novel, based on his previous career as an actor] didn't do very well, and I expect that to continue."
This month, the long-awaited film of One Day is released. It was directed by Lone Scherfig (An Education), Nicholls wrote the screenplay, and it stars Anne Hathaway as Emma and Jim Sturgess as Dexter. Will it be a hit? I can't possibly say, but I will tell you that my sense of outrage at the casting of Hathaway, an American, has yet fully to fade. Like lots of women, I am proprietorial about Emma, who is, like me, from the north, and who attended, and at roughly the same time as me, an unexpectedly posh university – Edinburgh, in her case. "I don't think you're the only one," says Nicholls, with a smile. Naturally, though, he sticks up for her: "There is a petulance and an insecurity about her that is just right. I think they're both terrific."
He likes the finished film a lot: some bits look exactly as they did in his head. But he also wonders if this will be the last time he adapts his own work. "I enjoyed doing it, but I think a fresh pair of eyes isn't the worst thing in the world. You can never quite shake off the book, and when something isn't working in the script, there's a voice in you head saying: well, it worked in the book. I cling to things a little too tightly because I wrote them."
Were Emma, so sardonic and yet so soft-hearted, and Dexter, such a dreadful show-off until life bites him on the bum, based on real people? (Emma is first a waitress, then a teacher, and finally a writer; Dexter works in television, and later in "artisan foods".) "Dexter less so. When I was an actor, I worked with lots of men who had a bit of success early on, who were very good looking, who suddenly made a bit of money and who felt no embarrassment – and nor should they have done – about having a good time. I think there are probably bits of them in Dexter. In Emma, there are bits of me, and my friends, and bits of fictional characters, too: Shirley MacLaine in The Apartment, Katharine Hepburn, Beatrice in Much Ado, a bit of Annie Hall... characters I love. I loved writing her. I found that attitude to life – the combination of moral seriousness and a kind of wryness – so beguiling."
For a while, Emma takes up with a terrible arse-scratching failed comedian called Ian (in the film, he's played, scene-stealingly, by Rafe Spall). "Yes, it's funny: when I was writing the novel, I thought Ian would be a Rafe Spall part. There's a lot of me in Ian. I had the same lapses of taste, the same terrible flat, the same gaucheness."
What is wonderful about One Day – this, surely, is the reason people love it so much – is the way it takes the reader so vividly back to being young: the supreme hopefulness of it, but also its inherent humiliations. How, I wonder, has he, a 44-year-old man with a mortgage (or maybe not, these days; he tells me later, very sweetly, that he is still "formulating a gracious way" to talk about money) managed to stay so in touch with what that feels like? Nicholls smiles. Or perhaps it's a wince. "That post-university time, I found very difficult. I loved university so much: I'd found my vocation, and that was being a student. It wasn't that I didn't want to grow up. But I didn't feel able to do all the things my parents had done in their 20s: buy a house, settle down to a career, have a family. It was a restless, anxious period and it went on for a long time. Adulthood came quite late to me, so that part of my life was extended. I didn't work full-time as a writer until I was 33. When I started this book, I didn't have kids. When I first met my partner, Hannah, I was still living in a basement flat in Stockwell."
Nicholls grew up in Eastleigh, Hampshire. His father worked in a cake factory as a maintenance engineer, his mother worked for the local council. "I was the first in my family to go to university [he read English and drama at Bristol], but I was going there to study poetry. So my parents were simultaneously very proud, and a bit concerned. They were certainly concerned afterwards, when I spent eight years in bedsits." After college, having won a scholarship to study acting in New York, he returned to London to pursue a career on stage and screen. Except the work arrived only sporadically. "My 20s was a sea of worry. I worried about benefit forms, about being thrown out of my flat. I never went on holiday because I thought: what if an audition comes up? I was a nervous wreck."
What made him finally pack it in? "A couple of jobs I didn't enjoy. I'd been an understudy in Arcadia [by Tom Stoppard] and as Konstantin in The Seagull, and I loved both of those, but then I had a couple of jobs where I was miscast and I was bad, and I was aware of being bad. By this time, though, I was reading scripts freelance, and I realised that what I liked about acting was the writing. Then again, I thought it was arrogant and presumptuous to ask people to perform something you'd written. Why would they want to do that? In the end, I was forced into it by friends. I wrote a sitcom script and then a film, and they gave me deadlines. I remain very grateful to them for that."
A chance meeting led to the writing of a one-off television comedy-drama, I Saw You, starring Fay Ripley, then at the height of her Cold Feet fame. "And that got me on to the Cold Feet writing roster. That was my big break." But didn't television – this is what I've read – make him unhappy? He smiles. "Only when I started to have failures. I loved it until then. Some writers have a gift for series: Russell T Davies, Paul Abbott. I don't think I was one of those. At 11am the day after broadcast, you get this awful, terrible call which is like being in a trial and waiting for the verdict: the overnights [ie the viewing figures]. I found that gruesome." So, he took some time off. Starter For Ten, the story of a student whose sole ambition is to appear on University Challenge, was a monologue that became a novel. When Richard and Judy picked it for their television book club, he was on his way.
The question now, I suppose, is: novels, or screenplays? Nicholls wants to continue to do both. He hasn't started the next novel yet, but he has written the screenplay for a new film of Great Expectations (Helena Bonham Carter will play Miss Havisham, and Ralph Fiennes, Magwitch), and you can almost feel his excitement about it. But this is not to say we should get carried away: the green light doesn't always flash instantly on, not even for David Nicholls. "A thing that makes me ache is a script I've written for Tender is the Night [by Scott Fitzgerald]. I wrote it for Fox a couple of years ago, and it does the rounds: it's always looking for a director, and someone to play Dick. I would love that to happen. That's my dream project. I'm obsessed with that book: it's so heart-breaking, and bittersweet, and lyrical." Nicholls is determined, even at the crest of what feels to me very much like a wave, to tell it to me like it is. "That's the thing about a film script. It doesn't matter how much of your heart and soul you put into it, it's still an instruction manual, and if someone doesn't make it, it doesn't have a purpose."
One Day opens on 24 August