The mental barrier between the sorts of things we do at home and at work has collapsed, writes LUCY KELLAWAY

THERE IS a new man in the office who sits at a desk just behind mine. Most mornings he’s in early, as am I, and as I leaf through the newspapers, I hear a rustling sound and the ring of metal on china followed by a slurp-munch-slurp noise.

I look around and see that he has pushed his keyboard aside and at his elbow is a box of Fruit ’n Fibre. He is eating his cereal intently, staring at his computer screen. Presently, he gets up, takes the bowl to the sink, washes it and returns to his desk.

I had been monitoring this breakfast ritual for a couple of weeks when I got an e-mail from a reader telling me that at the bank where he works, his colleagues’ desk drawers no longer contain files, but are filled with cereal boxes.

“What’s going on?” he asked.

It’s an interesting question.

It makes no sense to eat cereal at work. It takes about 90 seconds to prepare and eat a bowl of Bran Flakes at home. The fridge is to hand, as is the dishwasher.

In the office there is a trek to the fridge and you have to wash the bowl yourself.

The fact that workers overcome such odds to eat their Cheerios at their desks suggests that the mental barrier between the sorts of things we do at home and the sorts of things we do at work has now collapsed.

Over the past decade there has been a steady onward march of objects, activities and emotions from hearth to cubicle, so there is now almost nothing left that belongs entirely at home.

Modern office workers can conduct all their most intimate morning rituals at work. They turn up in sweat pants, take a shower, clean their teeth and apply make up.

Offices double as wardrobes and laundry rooms with damp towels, spare clothes and shoes strewn carelessly around the place. On the hat stand behind me are a pin-striped jacket, a couple of T-shirts, a pair of chinos and a week’s worth of dry-cleaned shirts belonging to the new boy.

Grooming complete, workers present themselves at their desks, where they are greeted by stuffed toys, rugs, bunches of flowers and, of course, photographs of children and pets. Even this evidence of home life is not enough. Now our children themselves pitch up to the office on a fairly regular basis, and some offices even welcome dogs.

Differences in what we wear and how we behave at home and work have been steadily eroded.

We may still be marginally smarter and more polite in the office, but it’s a matter of degree. Crying and shouting are both deemed perfectly acceptable, as are jeans and flip-flops.

It is even okay to sleep on the job – it’s called a power nap, and a few offices have installed beds or sleep pods to make it easier for us.

Sex, drugs and rock ’n’ roll are part of office life, too. The first and the second are officially forbidden, but still practised when no one is looking.

Rock ’n’ roll can now be done quite openly at work, thanks to the iPod, which allows us all to pass the dull hours in the company of Mick Jagger, or similar.

Technology blurs the divide in other ways too: we watch television at our desks, keep up on Facebook with who did what last night, do our shopping online and get the parcels conveniently delivered to our desks by the office post boy.

So is there nothing left that we do at home but not at work? I’ve searched long and hard, and found fewer than half a dozen things that have yet to make the journey.

There is still a taboo on nudity in the office, and I don’t think I’ve seen anyone at a desk wearing a pair of flannel pyjamas. Neither have I caught them knitting or daubing oil paints on to an easel, though that may be partly because hardly anyone does such things at home either.

There is only one thing that people choose to do at home but not at work: to give birth, though this can’t be far off. One colleague recently sent me an e-mail about a work matter as she was being wheeled into the delivery room, so to have the baby in a birthing pool on the floor at the office would seem the logical next step.

There is one final activity that we do less and less of in the office – work.

But this makes perfect sense: there is no point in working there when we can do it so conveniently at home instead.