The first time I fainted was on the bus. I was standing on the bottom deck, gazing out of the window (this was pre-smartphones, so playing Candy Crush was but a pipe dream), when suddenly — thud. Here’s what it feels like to faint. First your head starts swimming. Then you get tunnel vision. Tiny coloured spots — like a television that needs tuning — dance in front of your eyes.

You know you’re going to fall and there’s no point in fighting it. It’s frightening. Moments later, you come to, slumped on the floor of the No 57, covered in a film of cold sweat, your face a very odd shade of grey-green. Oh, and no one gives a fig. Presumably, they think you’re steaming drunk, in the middle of the afternoon on a Tuesday.

I’ve fainted on the Tube, in the street, the pub and in shops. Although, amazingly, not Ikea. Not once did a single person proffer the smelling salts. What’s more, nobody passed out in sympathy. The cheek. Because — hadn’t you heard? — fainting is having a moment.

Indeed, it’s the subject of a new film, The Falling, which tells the story of a fainting epidemic at a girl’s school in Sixties Britain. It’s already had rave reviews, and I’m not surprised. There’s just something about fainting that fascinates us. Perhaps it’s the idea that you could be going about your life and then — bam! — fall down, entirely at the mercy of your fellow human beings. It’s a little spooky.

Certainly, when I’ve mentioned my own experience, people demand to know more. How? Where? Did I see stars? And I’m sure I can’t be the only one who practised fake-fainting with school friends, throwing our arms up, sighing in a dramatic fashion and, occasionally, deploying these moves in achingly dull lessons.

Even more gripping are cases of mass fainting, as depicted in The Falling. Bizarre as it sounds, it does happen and mostly to girls — 90 per cent of episodes occur among women. Just last summer, in the remote Colombian town of El Carmen de Bolivar, 240 girls were struck down by unexplained fainting fits. In 2012, a school in New York saw dozens of students mysteriously pass out. And in 1999, Coca-Cola withdrew 30 million cans from sale in Belgium after schoolgirls complained of blacking out after drinking it.

A friend actually witnessed it during a work meeting earlier this year. A woman fainted (one way to get out of a dry presentation) and, within minutes, two colleagues had also collapsed. In none of these cases was a medical cause identified. Each was later attributed to one thing: collective hysteria.

No one knows why mass fainting happens. Psychologists have theorised that girls share their symptoms more and are suggestible. It’s generally agreed that there’s a “trigger” — a perceived odour or illness — that sets us toppling like hysterical human dominoes.

“Hysteria”, of course, is a rather loose term. It conjures up images of teen girls being carried out of pop concerts, having passed out in a frenzy of hormonal excitement. It brings to mind Jane Austen heroines having attacks of the vapours, and swooning, sexually repressed Victorian ladies.

Certainly, 18th and 19th-century women fainted more than we do. Blame is often placed on their tight, woollen dresses and corsets. But some of it was surely faked. It was considered fashionable among upper-class women (costume dramas don’t usually depict overwrought peasants dropping down in fields, do they?) “It was good femininity,” I’m told by the historian Professor Kate Williams. “Women were congratulated for letting their body reveal their emotions. It was a fit way to respond to something overwhelming.”

Police constables even carried smelling salts to revive delicate ladies. Can you imagine today’s Police Community Support Officers doing the same? You’d have revived yourself before they’d located their health and safety regulations.

We might be fascinated by tales of fainting. But, as I’ve discovered for myself, we’re all-too-often reluctant to intervene. Whereas, once, the local bobby would have been at your side in a jiffy — or maids would have fanned you frantically with lace handkerchiefs — today, it can be a rather isolating experience. So next time you see someone clinging madly to a seat on the bus and trying not to tip over, don’t turn the other way. They might be about to faint. Why not offer them a hand, or a sniff of your morning cappuccino at the very least? It’s not catching, honest.

— The Telegraph Group Limited, London 2015