It was the hottest day of the European heatwave and I was preparing for a dinner party in a Roelofarendsveen, a quiet Dutch village 30km south of Amsterdam.

I’d cycled to the local supermarket to stock up on supplies, and as I passed through the checkout I chatted to the cashier as we reflexively do in New Zealand. How has your day been? My gosh – it’s so hot! When you do think this will break?

The silence made me glance up from packing my groceries as the cashier blinked back at me, startled and unresponsive. My partner laughed and explained in Dutch: “Don’t mind her – she’s a Kiwi!” Smiling awkwardly, the cashier nodded goodbye.

It was the beginning of a month of constant social faux pas. Squeezed on sweaty trains in the London Underground, I’d smile at my fellow passengers if our eyes met, only to be frozen out with a quick, averted gaze. Ordering coffee in Kensington, I’d ask the barista if he’d enjoyed the Serena-Murray pairing, the cricket, and just what’s up with this heatwave, eh?

“Yeah, I don’t know,” was the usual monosyllabic reply.

Confused, I sat down with my editor in Kings Place, after another silent ride on the tube. “I’m realising small talk’s not quite the thing here,” I said to him. “I’m annoying people.”

Recently returned from a few years living in Australia, he understood immediately: “It took me months to learn to hold my tongue again.”

Gently, he laid out his theory. In crowded cities, cities with 10 million lives and more, people cling to whatever snatches of privacy they can get. Bell jars are not prisons, he said, but sanctums of peace – a chance to be alone with your thoughts, undisturbed, in metropolises teeming with competing lives, agendas, interests and moods.

Aimless chit-chat isn’t a friendly overture, as I understood it, but an unwarranted interruption, even a rude and misguided assumption that you’re entitled to someone else’s time, space and conversation.

You – a stranger!

Oh, I replied, deflated. That actually makes sense.

But even knowing the rules, it was hard to hold back. In New Zealand, small talk flows so easily, a ceaseless background banter you become inured to and engage in unthinkingly. And it often goes so much deeper than exchanging shallow pleasantries.

A casual enquiry of “how’s your day been?” at the supermarket can be greeted with unhurried tales of a mother just admitted to a hospice, a baby who won’t sleep or a husband who has been posted overseas for too long.

Trying to catch up on your emails in a taxi is fruitless, because the driver will want to know who you are, where you’re from, what you do and why you’re here. Not engaging makes me uncomfortable and is considered socially rude; a display that this person is not entitled to your time and attention.

When in New Zealand – they are.

We are small here and the population is not large. Isolation and loneliness are more pressing issues than overcrowding. The latest census shows more people are living alone than ever before, and young people are single for longer, while older groups might be widowed and no longer in the workforce or easily mobile.

Chat isn’t just chat in New Zealand, it’s connection, possibly the only social interaction of a person’s day, if they are isolated, out of work or lonely. I have been all of those things, and I have valued casual exchanges as proof that I’m still human, still worth talking too, when my feelings and mind seem to be telling me otherwise.

Early immigrants to Australia and New Zealand were often attracted by the prospect of a more egalitarian, classless society – a society where the prime minister shares a cup of tea with the plumber. (Though in Jacinda Ardern’s case, she actually does her own plumbing). It’s not true to say New Zealand has achieved this ideal. But it may be more true here, more of the time, than for many of our western neighbours.

After a month in Europe, we flew back to New Zealand, back to work and early nights and pets. As I stood in the duty-free shop, browsing the bottles of whisky, a ruddy-faced Otago farmer ambled up.

“Phew!” he said. “How good is that fresh snow?”

For a moment, I baulked. Did I know this man, this middle-aged farmer in a checked shirt and crushed baseball cap? Had I forgotten his face?

As he chatted on, I realised we were strangers. Strangers talking about the melting glaciers up the west coast. Strangers swapping details of the terrible meals we’d eaten onboard. Strangers who had time for each other, who weren’t in a hurry – who were home.

Eventually, he wandered off, fetched by his wife who’d finished her shopping. My partner approached, a bemused look on his face. Did you know him, then?

“No,” I replied, grinning. “I didn’t know him at all.”