While Batboy is in the air, I find myself thinking about the time Maria spent with us. I always feel sorry for tourists who fall into our hands: we are so insistently proud of the town. Every spare minute Maria was here, we showed her the wonders of Sydney. ‘Look at the Opera House. Isn’t it the most beautiful building in the world? We’re not leaving this spot until you agree with us that it is. I mean, how would you rate it, exactly, against the best buildings in, say, Europe?’

It’s that wonderful mix of pride, bluster and deep insecurity that says so eloquently ‘Australian’.

We certainly sent Maria back home with a very fine and detailed knowledge of Australia. Not only of the Opera House. But of the flora and fauna as well. ‘Isn’t that koala amazing?’ I say to her, as we walk through the animal park. ‘And, quick, look at the wombats—how cute are they? The platypus, you know, is one of only two monotremes. And the Tasmanian devil is facing an amazing and terrifying epidemic of disease within Tasmania.’

With an exchange student to educate, I’ve suddenly turned into an effete version of the Crocodile Hunter. Everything is amazing, fantastic and incredible. Half-understood facts from school come tumbling out. Australia had a gold rush in the 1850s, I tell her. The gum is a sort of eucalypt. The wombat has a backward-facing pouch so that dirt doesn’t fall in while it is digging.

I haven’t had a chance to expound this stuff since Year 5 and I seize the opportunity with enthusiasm. Suddenly, I’m the Professor of All Knowledge; each barely remembered fact a jewel to place before the visitor. The merino is Australia’s leading sheep. Pineapples are grown in Queensland. Australia has a bicameral system of government. I can’t quite remember what a bicameral system of government is but it seems unlikely she’ll ask. By this time we’re driving home, and in the back seat of the car, Maria appears to have fallen into deep, deep slumber.

We pull up outside our place and Jocasta tries to awaken the visitor. ‘Australia has nine of the ten most deadly snakes in the world,’ Jocasta insists, as she tries to shake her awake. ‘There are six states and two territories. And the water in the plughole goes the other way around.’

Maria is unfailingly polite. ‘Really?’ she says, squeezing her eyes open and shut to dislodge the sleep. ‘How fascinating.’

‘Oh, yes,’ I say, ‘and Burke and Wills got lost near a tree. Plus, the Hume Highway is named after an explorer called Hume, who grew up in a hovel. And Tasmania was circumnavigated by a man called Flinders, who was accompanied by a cat. The cat, of course, was later used to punish convicts in a way still not understood by historians.’

Says Maria: ‘And, please, why does the water go the other way?’

‘Ah well,’ I answer, as we walk towards the door, ‘that would be because…’

‘Because,’ Jocasta says, coming to my rescue, ‘because of the way Australia is…’

‘On the bottom of the world,’ I take over.