The Couch Surfer: 'One Day looks like the sort of book you'd only buy at the airport. It's not'

I don't often find myself awake at one in the morning with big fat girly-man tears rolling down my cheeks.

No, honestly, I don't. Not yet. But the last 40 pages of David Nicholls' novel One Day, which I pushed on through one school-night last week, were almost unbearably moving. Maybe it was the alcohol from earlier in the evening; maybe I need to start wearing spectacles; or maybe I was just tired (it was one in the morning, after all). But I blubbed. In fact, as time goes on, I find myself welling up more frequently than ever, or at least since I was a toddler and thought it might get me sweets.

Nicholls' first book was Starter For 10, a university romcom that was made into a movie starring James McAvoy. He's a purveyor of what appears to be chick-lit for chaps: "dick-lit". One Day is the story of Dexter and Emma, who cop off on their graduation day – St Swithin's Day, 1988, to be precise. Each successive chapter is set on the same date, every year, for the following 20 years, as Dex and Em move in and out and back in to each other's lives again. The structure sounds pat, the premise populist. The cover is neat and cleverly designed, with a complimentary quote from Tony Parsons at the bottom. It looks like the sort of book you'd expect to buy only at the airport before a long flight.

Yet the characters (both media types who drift to the middle-middle class from the upper-middle [Dex] and the lower-middle [Em] during the New Labour years) get whisked up in the social currents of the times, from the tail end of Thatcherism to the Iraq War. And onto this historical backdrop Nicholls draws a funny, warm and wise portrait of quarter-life, full of all the joys, compromises and disappointments of growing up.

As the decades accumulate, and as the distance between the young Dex and Em and the less-young Dex and Em increases, they come to better understand their own feelings – happiness, loneliness, love – and no doubt readers will appreciate it more the closer to 40 they are. Buy it for an appropriate family member (preferably a male one) for Christmas, leave them alone in a room with the book and a bottle of brandy. I defy them to keep their eyes dry.

Are we more susceptible to the emotional manipulation of art as we grow up, or merely less embarrassed to feel than we were as teenagers? I seem to have stumbled into a hinterland of previously uncharted emotion somewhere in my mid-20s. In her new collection of essays, Changing My Mind, the preternaturally precocious Zadie Smith admits weeping at a novel – a serious, worthy one about race and gender, at that – when she was just 14. Perhaps moments of fictional feeling simply resonate more strongly with your own experience the more mature you get.

Sometimes the tears are relatively meaningless: I cried at The Queen, but only because I was deeply hungover. I emerged from Avatar red-eyed, but only thanks to the £16.50 cover charge and the strain placed on my retinas by almost three hours of IMAX 3D. I don't cry at the merely sad; Holocaust movies often leave me cold. I cry instead at the bittersweet: at The Diving Bell and the Butterfly, or Eternal Sunshine of the Spotless Mind. The bit at the end of Good Will Hunting when Ben Affleck knocks on the door and Matt Damon isn't there. The bit in Robin Hood: Prince of Thieves when Kevin Costner finds out Christian Slater is his brother.

Watching films on planes is especially dangerous; my mild fear of flying must make me fragile. I once saw Walk the Line and Pride and Prejudice back-to-back on the way home from New York and went through a whole Kleenex pocket pack. I'm fortunate that a friend gave me One Day, otherwise I may indeed have picked it up at some notional airport and gone on to regret it at 30,000 feet.

This is only going to get worse. Dexter and Emma are a good 10 years older than me before their story ends, and their emotional journey towards contemplative, melancholy middle-age continues on the same trajectory. They weep a lot more in the Noughties than the Nineties. If one of this newspaper's elder statesmen is to be believed, soon it won't just be narrative works – books, plays, films – that undam my tear ducts. It'll be lines from Larkin poems, the reds in a Rothko canvas, Coldplay songs, even cricket matches. Apparently, as and when I have children, the mere word "little" will set me off. I'll be standing in the freezer aisle at Tesco, sobbing uncontrollably over the petits pois. "They're just... *sniffs* so small!"