It’s commonly attributed to either Mark Twain or Ernest Hemingway, though I’ve no idea what became of them – but it’s become one of the best-known and most hotly debated precepts of creative writing. So I thought I may as well give it a go.

But that begs the question: what do I know exactly? I know a bit about a fair few things, but not all that much about any. When I do understand a subject in more depth than most, that’s usually because it’s so niche as to be virtually unknown. To this day, I could probably name most of the players who featured in my 1985-86 Panini football sticker album. I have yet to find a practical application for this.

Anyway, apart from a handful of things that have somehow tattooed themselves onto my brain – that sticker album again – what I know is necessarily transient. At various points, I could probably have claimed a decent working knowledge of stock control, food science, corporate risk management or Chaucer. But not all at the same time, and certainly not now – because with neither the incentive nor the enthusiasm to retain that information, it’s slowly but inexorably exited my brain like bathwater down a partially blocked plughole.

So rather than asking myself what I know in general, perhaps I’d be better asking what I know most about right now. And as the parent of a child approaching the age of three, I do at least have a straightforward answer to that question: Bluey.

If you haven’t had to entertain or placate a small child recently, it’s possible you might not appreciate what a colossal deal Bluey has become in only seven years. Last year it was the most-watched TV show in the US, with a total streaming time of 55 billion minutes – or, if you prefer, a little over 100,000 years.

Its merchandising has rapidly caught up with its fellow pre-school behemoth Peppa Pig in terms of UK shelf space, and you’ll struggle to find a playpark without at least one child – possibly ours - clad head to toe in Bluey regalia. Inevitably, a film is in the works.

In short, Bluey ought to represent everything I hate about the corporate world and its cynical monetising of children’s entertainment, to the detriment of children and parents alike. (Exhibit A: Cocomelon. If you know, you know.) But there’s a reason why I feel differently about Bluey: it’s utterly, consistently brilliant.

Bluey creator Joe Brumm might be the ultimate case study in writing what you know. He grew up in Brisbane, where his family owned a blue heeler dog called Bluey, and is married with two daughters. Bluey is set in Brisbane and features a married couple of blue heeler dogs and their two daughters.

Parents love it as much as their kids, because the whole thing is aimed at both generations at once – and not in the panto style of slipping various ‘adult’ jokes, designed to go straight over the children’s heads, into the script. In Bluey, the same jokes are aimed at everyone equally, and the parents learn from the kids as much as the kids do from the parents.

As it became apparent that the show was primed to take over the world, if anything it became even more homespun. Whole episodes are based around uniquely Aussie words like ‘dunny’ and ‘dobbing’, which are never explained. A recent episode is essentially a parable of how cricket makes the world a better place. To reiterate, last year Bluey was the most-watched show in the United States.

It’s enough to convince me that the saying really does hold true: write what you know. Don’t try to write everything you know, or write it in an entirely realistic way. (After all, much of Bluey may be drawn from Joe Brumm’s own experiences, but importantly, he’s not really a dog.)

But don’t try to write what you don’t know, based on some vague notion of what people want to read. People – young and old – love good writing that captures some sense of shared experience. Bluey does that as well as I’ve seen, and as a result the world now knows what a dunny is.

If someone reading this is suitably inspired, maybe one day we’ll be celebrating a global TV phenomenon featuring a family of Leith-based hamsters and an episode called ‘Cludgie’.

We can but dream.