Rhodri Marsden: Mattress adverts – the greatest lie the devil ever sold

We know that the advertising industry has to paint unrealistically positive pictures of our attitudes towards every product, whether it's people weeping tears of gratitude at a payday loan, laughing hysterically at pasta or growing extra limbs at the thrill of test driving a Toyota Yaris.

But selling a double mattress involves imagery so far removed from human experience that they may as well use a picture of one being dragged around Atlantis by a unicorn. I'm looking at one such advert right now. A slumbering man and a snoozing woman, draped over each other artfully, both exuding a self- satisfied smugness because they've each had a blissful eight-hour kip and are fully prepared for whatever the day may throw at them. Drizzle, war, anything.

It's certainly never been like that for me, despite mattress widths expanding over the years and boosting the distance between me and a vaguely sleeping partner. In an ideal world, double beds would be 36ft wide and have a soundproof wall erected down the middle that's reinforced with barbed wire and patrolled silently by guards walking dobermans. But this world is not ideal. We have limited patience, funds, space. Frequently there's no spare room to run to. We're stuck. And we're awake.

I know it wouldn't sell many mattresses, but a more accurate portrayal of bed- sharing would involve that same couple looking into the lens with a demoralised, dead-eyed stare, one of them with a blue-ish tinge after having spent the night losing the battle of who gets the duvet, the other wondering anxiously if their partner's hourly visits to the toilet are indicative of a serious genitourinary infection.

If we had any sense we'd opt out of co-sleeping altogether and only unite for sexual summits in neutral territory (corridors, etc) but society expects couples to spend hours of silent semi-consciousness within inches of each other, regardless of whether they're massively pissing each other off. If they don't persevere, they've failed. A whole industry exists to keep us lashed together at night, selling snoring remedies, earplugs, eye masks, sleeping aids, relationship counselling and memory foam. But no amount of memory foam is going to stop your partner accidentally smashing you in the face with their forearm halfway through the night while mumbling something incomprehensible about chickens. "Ouch!". "Huh?" "Nothing." "Chickens." "Whatever."