Bianca promised to drive me to the 24-hour Kmart in East Burwood, Melbourne, because I wanted to see what people need to buy at three in the morning. Bianca goes for long drives alone, late at night, when she cannot get to sleep. On these drives, she discovers such places.

She was named after Mick Jagger's first wife, because her parents liked the name and they liked the Rolling Stones. We'd grown up around the block from each other, in Braybrook, a suburb filled with factories and steel-framed skeletons of stripped-away buildings. When I was a child my parents kept me carefully reined, between four walls; Bianca was free to wander the streets, carefully, but at will. Her driving habits are similar.

At 11.15 pm, Bianca turns off the Burwood Highway, and suddenly we have arrived. It is a massive building rising out of the dark, and the blue and red sign is like sky-graffiti, with the ‘K' kicking through the night. The letters spell out a landmark loiterer's paradise in the middle of dark suburbia.

Burwood is the site where Australia's first Kmart opened, in 1969. The store's slogan is "Where good times start", and when it debuted, this flagship American import was flooded with ladies in pillbox hats and twin-sets. The car park was jammed with HD Holdens and Valiants, and people lined up for the promise of good times. But the good times could only stretch for so long before they snapped back, like gum chewed too long, and became tasteless.

Tonight, this place filled with polymer and polyester goods no longer promises excitement for its temporary inhabitants. It has become an alleviator of our boredom. Tonight, the store is so shiny spick-and-span that we forget we are standing inside a piece of Australian history. At 11.30, when we walk through the automatic doors, it is as if it is still daytime. The first inanimate object of consumer desire we see perpetuates this delusion: out the front, in the foyer, is a Professional Titanium barbecue displayed for the special price of $599. I wonder if anyone has ever thought of the Great Australian Outdoor Eating Dream at two in the morning, and decided to buy one.

There are whole families inside the store: wide-eyed kids staring at shelves in the toy section, a small boy on a yellow scooter. Dads examining gardening tools and mums loading their trolleys with discounted tissue boxes. People looking at the most ordinary and useful things in life: small clock-radios, car fresheners, tween underwear, fishing equipment, adhesive rolls of book covering, eggtimers. Here, time is suspended, and such scrutiny takes on an extra dimension. I realise how deeply complex shopping complexes are.

The Dalai Lama once confided that if he were not mindful, he could become dangerously attached to visiting supermarkets: "Everywhere I look, I see so many beautiful things." Inside this store, everywhere I look, is the work of a million different people from all around the globe. Bianca and I marvel at all the things a person could own, produced en masse by people we will never meet. This is everything we ever wanted when we were young, our giant playground, except that now we are cashed-up, sort of. We spend hours trawling through every aisle, trying on clothes we aren't going to buy because they aren't on sale yet. We can get our photos developed at three in the morning, if we so desire. In the confectionery section Bianca gets false teeth and a pair of lips, while I choose a packet of muffin mix.

Now there are no pillbox hats, but pillboxes on discount for 50 cents, and twin-sets come in enormous plastic-wrapped bundles from the factory floors of China. Now, people come to Kmart in their pyjama bottoms, like the Chinese students we see ahead of us: two young men and a young woman with fashionably dyed hair. The boy is dressed in flannelette bottoms and has black-rimmed glasses. The girl is wearing a dressing gown. Sleepy-faced, they swim half-dazed through the bright lights to find their distractions. They walk through the store with the familiarity of someone rummaging through their fridge at night.

Following them through the aisles, I pause and become smitten with cheap nylon yarn that comes in the colours of lollies and texture of feathers. Lost in a revelry of future scarves, I realise after a while that I have lost my three Chinese students. I glance around and see that Bianca has disappeared, too. Looking at my watch, I realise that it is already 12.26. I wander over to a sales assistant, a pretty teenager whose face is deliberately aged by Maybelline. She is attaching stickers to boxes of DVDs.

"What do people buy at three in the morning?" I ask.

"Oh, you'd be surprised. The big-ticket items they don't usually buy during the day. PlayStations. Bedding and manchester. Sometimes bicycles."

"What about barbecues?"

"Yes ..." She pauses. "But not often, because they need to be delivered, and people at night like things they can drive home with in the back of their car."

I ask her about her shift, and she tells me that she began only half an hour ago, and works until 8 am. She says that she enjoys this shift because it is more relaxed.

A middle-aged Vietnamese couple passes us. They are decent-looking people dressed in Kmart tracksuit pants, mildly marauding the aisles searching for household goods: pillows, chairs, mirrors, tumblers ($3 for 12 long glasses). Two Indian men have sacks of beanbag stuffing in their trolley and are wheeling it to the register. Along the way, there is a shatter: they have accidentally knocked over a tray of tumblers with the trolley. The security guard near the front register approaches them, probably to tell them to pay for the damage.

At around 1 am, there is a 15-minute reconciliation. This is the only time that the registers are put on hold and customers cannot make purchases. We are warned far in advance of these 15 minutes by the in-store PA system, which interrupts the in-store radio broadcast. A soundtrack of music, news updates and promotional segments is the backdrop to this buyers' heaven.

Bianca drove us here partly because she wanted a blender to make smoothies. She gets one with a glass cup for $35. We don't feel like consumers, because we can muck around here until daybreak if we want. We line up at the cashier at 3.14, and I tally up what I have brought: a striped jumper for my sister, a red cardigan for me, a tin of blush for Bianca, a lamington tray, my packet of muffin mix, a scrubbing brush with a holder shaped like a blue frog, a pencil-case for my brother and a toilet block that smells like lavender. I had only meant to accompany Bianca on her trip, and write about the strange things people brought at strange times. But somehow, surreptitiously, in the slow dreaming hours, Kmart has seduced me into becoming her shopping accomplice. Bianca and I emerge into the sharp navy night and head towards the car, feeling strangely excited and fulfilled. We cannot wait to open our white plastic bags.