It must be about 25 years since the Rat first made an appearance in The Spectator. He started out as my girlfriend’s six-year-old boy, then became my stepson and featured here quite often over the years because, being a scaly-tailed creature of evil, he was always good for some copy. This new year, with his agreement, I upgraded him to full son status. Let me explain why in a way that I hope you’ll find charming, rather than one that makes you want to throw up.

The first reason is purely mercenary. During Christmas, while over with his wife Chloe from Hong Kong, the Rat managed to find about £10,000 down the back of my virtual sofa, in the form of seven Bitcoin Cash that I thought I’d lost forever. Then he found another half a Bitcoin (BTC) which I also thought I’d lost, bringing the total free money found to well over £15,000.

How can I possibly have lost such large sums of money? Very easily, as any technologically illiterate cryptocurrency owner (we do exist) could tell you. The digital wallets where you keep your BTC and so on are not the most secure or stable places, especially if, as in my case, you got yours several years ago when Bitcoin weren’t so valuable, then more or less forgot about them and failed to upgrade.

Multibit, the wallet I stored my BTC in, was so old it was no longer supported. The people who’d invented it had given up and moved on. This wasn’t good news if you held BTC in it in September last year, because that was one of the moments when the crypto-currency ‘forked’. That is, the currency had a kind of scrip dividend and for every BTC you owned you were also allocated some of a new breakaway currency called Bitcoin Cash.

Unfortunately, because Multibit was so old, it didn’t automatically give you your Bitcoin Cash as other more modern wallets did. When I discovered this I tried not to think about it too hard, especially when I noticed Bitcoin Cash going up and up in value. It’s never a good feeling when you realise that, through a mix of inertia and incompetence, you’ve managed to cheat yourself out of thousands of quids’ worth of free dosh.

But I didn’t give up hope altogether. The first thing I did was a bit of Googling to see if there were any other losers in my predicament. Yes: it turned out there was a way to reclaim our Bitcoin Cash. We simply had to load our Multibit wallets on to a more modern wallet using our private keys.

Wait. ‘What the hell is a private key?’ I wondered. And found, to my horror, that this was the sequence of 12 random words — a unique, uncrackable code combination — which I was supposedly given when I first got my Multibit wallet four years ago. Except I never remembered seeing them, let alone writing them down. Just in case, I spent days ransacking all the drawers and notebooks and computer files where I might conceivably have jotted down the code. No dice.

By the time the Rat and Chloe arrived, I’d had it to the teeth with cryptos. Apart from the misery caused by my vanished Bitcoin Cash treasure hoard, I’d also lost many thousands of pounds more — on paper, anyway — because of that sudden pre-Christmas crash which, at one point, saw my meagre BTC holding halve in value. And I’d been unable to ask the Rat what to do because, with perfect timing, he was on the plane when the crash happened. I’d tried to sell one of my BTC, before it lost all its value, but the exchange I used was so sclerotic that I couldn’t even give the wretched thing away…

Once the Rat arrived, however, order was restored. Not being cursed with any of my genetic make-up, he possesses certain special qualities that I lack; one of them being slow, methodical patience, especially where technology is concerned. Where my response to any computer-related problem that cannot be solved instinctively in seconds is to panic, then scream, then despair, Rat’s is to download the instructions, read them carefully and make things better.

Which is exactly what he did in the case of my Bitcoin Cash and also with that bonus half-BTC. Don’t ask me how he managed it. All I know is that the Rat’s electronic tinkerings gave us an extra-specially happy Christmas this year. It more than made up for last year’s yuletide fiasco when the Fawn spent the entire ten days vomiting, and when the Rat and his brother cost me £1,200 by burning out the clutch on the Land Rover while practising in the field.

Also, having the Rat back at home reminded me, not for the first time, how very lucky I am that he came into my life. At first I wasn’t sure of this. I was 28 when we met and at that age — this may sound harsh, but fellow early step-parents will understand — the last thing you feel like doing is taking responsibility for someone else’s kid when you could still be roaming free.

Rat brought this up during one of our many boysy chats, invariably involving cryptos, on which he has become quite an expert. ‘You realise I’m now older than the age you were back then. And you know what? If I’d been in your shoes then there’s no bloody way I would have taken on an evil brat like me. But I’m glad you did.’

Me too, Rat. And I think I might still say that even without the Bitcoin Cash.