Next week it’ll be forty years since Britain went decimal, and 12 pennies to the shilling and 20 shillings to the pound were replaced by our current multiples of ten. I was born three years after decimalisation, but when I was a kid in the late 70s and early 80s, it was a common thing to find old currency floating round our house. I’d collect the coins and keep them in a jar; the half-penny with a sailing ship on it, sixpences with their intricate rose design and my favourite, the chunky 12-sided three-penny piece with its portcullis.

As a child of a decimalised Britain, born so soon after the big change, the old currency has always had a bit of a romantic fascination for me. I grew up reading about it in books, never quite sure what the terms meant exactly, but knowing them intimately all the same: sovereigns, half crowns, shillings, farthings, thrupenny bits, tuppences, tanners, bobs. They’re lovely words that don’t seem to be matched by today’s prosaic quids.

The language of the old money is bound up with literature for me, because that’s where I experienced it. There’s something delicious about the thought of Sherlock Holmes pushing a weighty shilling into the palm of an informant’s hand in return for information, or wearing the sovereign on his watch-chain that he got as a tip while disguised as a horse groom .

The sixpence especially seems to have permeated our culture. Like a Homeric prefix, Sixpences always seem to be bright sixpences, new sixpences, shiny sixpences, given to boys like Richmal Crompton’s William for good behaviour (or rather, in William’s case, bad behaviour with unexpectedly good consequences.) There’s something magical yet obtainable about a sixpence, and even I, who’d never been tipped one, coveted them.

The mention of sixpences always reminds me of A. A. Milne’s poem Market Square, which starts out with a boy who has a penny to take to the market. “For I went to the stall where they sold sweet lavender / (“Only a penny for a bunch of lavender!”) / “Have you got a rabbit, ‘cos I don’t want lavender? / But they hadn’t got a rabbit, not anywhere there.” Returning with two pennies and then a “little white sixpence”, there are mackerel and saucepans at the market, but still no rabbits, until the boy goes to the “old, gold common”, with no money at all, only to find  “little rabbits most everywhere!”

I’m not alone in my love of the sixpence. There was even a campaign to save it after decimalisation, and it limped on for a few years, doomed to end up in jam jars of odds and ends across the country, a relic of another time.

I’ve still got my jar of old money somewhere. I’m going to show it to my kids, so that they know, when they’re reading Sherlock Holmes, exactly what a shilling feels like in the palm.