Perhaps that is putting it too strongly. After all Mrs Rock is actually in pretty good health and I'm certainly not suggesting that she is in "unwell" in the way that the famously dissolute Spectator columnist Jeffery Bernard was often described as "unwell". However Mrs Rock is more than a tad confused. In fact she's also more than a tad bothered because, on top of everything else, she has no real idea what a "tad" is. She thought she might look it up on her son's interweb thing.

We only seem to encounter our Gibraltarian matriarch at this time of year – the time of peace and goodwill to all, especially readers of The Gibraltar Magazine. So what is it that is troubling our compatriot this December? As always, her son Sheridan is to blame. The "family Christmas lunch" has come round again, the annual occasion when the family – at Sheridan's insistence – take stock of matters financial.

This year Mr Rock has declined the invitation. "Last year, that boy took us all the way to blimmin' Africa and tried to get us to buy an apartment there," he protested. Readers might recall the Rock's unsuccessful foray to Tangiers in 2013. "He wanted to shift us out of Gibraltar – international succession planning, he called it – and we spent most of the day being shouted at by an estate agent. He even kept insisting that Tangiers was actually called Tangier, as if the 's' had just suddenly been obliterated. I'm not putting myself through that again."

So this year's lunch was to be "à deux" – just Mrs Rock and Sheridan – and the invitation had just arrived. But what was this? Lunch at sea? The expensively printed card announced in beautiful italics "lunch on board Sunborn, the floating five-star hotel". Which is why Mrs Rock was a "tad' confused. Of course she'd admired the sleek lines of the massive vessel of course on her occasional visits down to Ocean Village. But this was from afar. It was quite a different matter to actually go on board for lunch. What would she wear and would she suffer from el mareo, which normally struck as soon as she stepped off a jetty? And where would the boat go? She wasn't up for going back to that Tangier – with or without an "s" – thank you very much. Oh no!

"What do you mean, it doesn't actually move," she said to Sheridan. She thought it very odd that the ship didn't go anywhere. "Like a cart without a horse", her dad might have said. Anyway the big day finally dawned – a beautifully clear Gibraltar winter morning – and Sheridan came to pick her up in that fancy new motor car he had just bought "with the bank's money, ha ha", as he said. He may have called himself a "financial planning consultant" but, as far as she knew, he didn't work in a bank. In fact there was a lot she didn't know about Sheridan but still, she was determined to enjoy her lunch and to get him to answer these financial questions that still troubled her.

So on board she went, passport in hand. "Put that away, mother", Sheridan hissed. "You didn't need to bring that." An elevator – just imagine, in a boat! – whisked them up to the top floor and, sure enough, there was a fancy restaurant with some even fancier waiting staff. They were ushered to a table and, before you could say "Anne Robinson", their orders were being taken. Mrs Rock didn't really get on with haute cuisine – all those funny names put her off from the amuse-bouches to the petit fours. So, much to Sheridan's horror, she ordered a well-done steak and chips with a small beer.

This done, she laid out her financial concerns to Sheridan. If Gibraltar's economy was doing so well, as the Chief Minister kept reminding her, why was she still not earning any interest to speak of on her savings account? And if Spain was in such a state, why was she not getting more euros (or should that be euro?) when she crossed over to go to Mercadona? And if we were coming to the end of the downturn, why were some people still so gloomy? Like Chicken-licken – who fortunately wasn't on the lunch menu – Mrs Rock had a tendency to believe that one falling acorn meant the sky would soon come crashing down on her head.

This was Sheridan's moment. Cometh the hour! He set about explaining the situation in the eurozone (how the euro was weak but the pound, in some ways, even weaker); the risk of deflation, a triple-dip recession, negative interest rates at the ECB and so on. Such was his enthusiasm for the subject that he failed to notice that his mother's eyes had glazed over and that her head had almost sunk into her half-eaten steak-frites.

Shaking herself awake just before chin hit plate, Mrs Rock interrupted: "I'm sure you know best, dear, but it's so much nicer when I read that chap who writes every month in the magazine." Sheridan rolled his eyes. "He's always so much more positive about things."

Sheridan was waiting for this. "Are you absolutely sure that chap actually exists, mother?" he riposted. "I mean have you ever seen anyone actually walking around Gibraltar in rose-tinted spectacles? He wouldn't be too hard to spot, would he? I think the editor of The Gibraltar Magazine has made him up – a bit like that Martin Lukes who used to write in the FT until they packed him off to jail." Mrs Rock had no idea who Martin Lukes was – but he certainly sounded like one of Sheridan's dubious acquaintances.

"So anyway, mother," Sheridan said. "There's no point in hanging around waiting for interest rates to go up. You should do what I've done and invest in bitcoins." "Really, dear?" Mrs Rock responded, not sure she had heard correctly, "What on earth are bit coins?" "They're not on earth at all," smirked her son, "they're in cyberspace. Bitcoins are the first fully implemented, decentralised crypto currency. There'll be 21 million of them by 2140." Mrs Rock glanced around at the nearby tables to see if anyone was staring at them because Sheridan seemed to be talking complete gibberish – or cobbledick as she preferred to call it.

"So, this is what I was thinking," Sheridan moved in for the kill. "As you and Dad aren't interested in buying an apartment in Tangier – er, I mean engaging in pro-active intergenerational succession planning – I thought perhaps you might to like to come in with me and join the bitcoin party. The price varies a lot, but that's where I – I mean we – can make money. Buying and selling and winning every time."

Sheridan was palpably excited. After all this was the future and his mother was always saying how concerned she was about his future. Mrs Rock stopped looking around, leaned towards him over the table. His excitement grew. "Do you have any bitcoins on you dear?" she whispered. "That you could show me?" "Um, no," said Sheridan. "I mean they don't really exist in a physical sense. The whole idea is that you trade them online and use logarithms to mine them."

"So they don't exist but you can mine them? With log-a-somethings?" Mrs Rock looked bewildered again. Last year had been bad enough with Sheridan's idea of buying a flat in Tangier that she and Mr Rock would never live in. At least she knew what an apartment was, even if it was on Boulevard Pasteur in Tangier. But really, buying non-existent coins on the interweb thing. This was really taking the biscuit. She finished her beer and refilled the glass from her son's bottle of Marques de Caceres. She needed something medicinal and besides, from the way he was talking, she felt he'd probably had quite enough. It was just like all that "surfing" that Sheridan claimed he did – when she knew he was at home in his flat! Perhaps his father was right. He did need to get out more.

She gulped down the wine in one go. "Well, dear, it's been a lovely lunch – thank you". She was sure she had just felt the ship move. Sunborn – son born. There must be something in that. In truth it was hugely impressive but she was quite happy when Sheridan walked her down the gangplank and back on to dry land. When she bade him farewell she reflected that she was just as confused as ever about her finances. Nevertheless, she smiled, despite the strange course that lunch had taken, she no longer felt unwell. And, she was glad to see, that chap in the specs from the magazine had sent her another Christmas card. Ah yes, the message inside was very reassuring ...

"With season's greetings and best wishes for a healthy and prosperous New Year 2015, on behalf of all the staff at Sovereign in Gibraltar".

Originally published by Gibraltar Magazine, December 2014.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.