Until that trip to North Wales, the first major outing with Dan, who was then aged eight months, he had slept like a top through every night since his birth.
But on that first night away in Plas Talgarth, when invited to sleep in a travel cot, he literally had the screaming hab-dabs. It was not his usual cot and he refused to sleep in it. He hoisted himself up and screamed. And screamed. Nowhere would do: not our bed, not me walking him up and down jigging him. He wanted his cot in his bedroom.
The only way he could be encouraged to sleep was to put him in his car seat and go out for a drive. Which was what we did at four o'clock that morning and heard that Princess Grace had driven down a precipice to her death.
I don't think Dan slept at night for the whole week. But in retrospect it wasn't such a bad holiday. The weather was hot and the apartment was good. I was surprised to discover that you can get used to living without sleep.
This was our first experience of holidaying with children. Until then our holidays had been agreeable excursions to France, America and the Far East, where we did what we wanted and pleased ourselves. If we had known what was coming, we might have endeavoured to please ourselves a bit more.
After North Wales we could have been forgiven for giving up on trips away. But a couple of months later we found ourselves crossing the Atlantic on the QE2 and ended up being stranded in the middle of the ocean during a Force 12 storm. Dan screamed, not so much because he missed his cot but because, like us, he was sure a sudden watery death was imminent. But we all survived and gradually he came to terms with travel - and we learnt how best to cope.
Jessica was barely three months old when we flew to Paris with her. She cried on takeoff and landing, as all babies do because of the pressure on their ears: but she was less bothered about abandoning the comforts of home. Dan, who by now was two, incurred the wrath of neighbouring passengers by attempting to break his aircraft seat down to its component pieces. 'Oh, il est terrible,' tutted one lady. (You come to learn that there is generally somebody around who will disapprove of what your children are doing or not doing.)
Having one child in a pushchair and another in one of those carrying straps on your front is a quick way to total physical exhaustion. I seem to remember lugging both children around the whole of Paris for an entire weekend. But despite the hard work, we all enjoyed it.
As the children grew up we learnt another lesson. Holidays do not necessarily get easier, they just get different. When you can lock them up in car seats and manacle them into pushchairs, children are largely at your mercy. You can go more or less where you want to go and they have no say in it.
Before they reach the age of reason, gites in France are a good proposition for a family. You can take the car with all the children's requisites. You will probably have a decent-sized garden to let them play in. In the evening, after they have gone to sleep, you can eat and drink in peace.
In 1985, when Dan was nearly three and Jessica was one, I was writing a guide to northern Spain and for three weeks we drove around Asturias and Galicia, staying at a different hotel every night. It was a delightful trip: the children slept as we drove each morning (we travelled from St Malo to northern Spain) and were happy to be dragged around an apparently endless succession of museums and cathedrals.
The cathedrals were a particular favourite: the children were delighted by the acoustics which encouraged them each time to offer an impromptu rendering of the Postman Pat theme. Flickering prayer candles would be blown out as they sang a rousing chorus of 'Happy Birthday'.
But it does not take long before they hate going anywhere in the car for more than half an hour. Within five minutes of leaving the ferry in France, they start asking, 'Are we there yet?' and repeat the question every 10 minutes for the next 12 hours.
And there soon comes a time when they want holidays which offer (dread word) 'fun'. Gites were quickly seen to be boring, since the only company on offer was dull old parents.
In 1986 we went to the Caribbean island of Grenada, where we stayed in a hotel that not only featured other children of their age but had rooms with satellite television. Not to mention perfect white beaches and a blood-warm sea.
Grenada was good, but even better in their opinion was a Canvas Holidays package we took later that year to the Dordogne. There was the fun of sleeping in a tent, plus the entertainment of a children's club with somebody organising games.
The following year, when Dan was five and Jessica was three, we went to Disney World in Florida. In truth they were both too young to enjoy it properly: there was too much walking in high heat and humidity. But it was worth doing just to see the expression on their faces when they met Mickey Mouse and got his autograph. (We have since returned to Disney World twice and we all enjoy Orlando more and more each time.)
The second week of that first Florida holiday, spent on Sanibel island, on the Gulf Coast, was probably more successful. The hotel had a swimming pool (and satellite television) and there was a big wildlife refuge nearby with eagles and alligators.
The best Mediterranean holiday we have had was three years ago in Paphos on Cyprus. At the hotel there was a children's club which kept them busy from 9am to 5pm. We were left to battle for sun loungers and doze peacefully next to the pool, while a tireless Scottish teacher engaged our children in a variety of improving and enjoyable activities.
Our most ambitious trip, and undoubtedly the holiday we have all enjoyed the most, was two years ago when we took a cheap Austravel charter flight to Queensland in Australia. I dreaded the thought of the 21-hour flight, but the children coped extremely well. Britannia Airways was geared-up to cope with them: there was plenty of in-flight entertainment and amusements.
Queensland, with its koala bears, fascinating rainforest walks and crocodiles, and the Barrier Reef, with its amazing brightly-coloured marine life, might all have been tailor-made for the pleasure of children.
In the three-week trip, which took us from Cairns to Canberra via Heron Island, Sydney and Melbourne, we never had a cross word. The food was familiar, the language was English and - joy of joys - after tea you could even watch Neighbours (albeit 12 months ahead of the plot-line in Britain).
I am pleased to say that Dan quickly overcame his eight-month-old antipathy to strange places. Both children now enjoy travelling every bit as much as we do. We do not mind them missing school: you are entitled to two weeks out of school under the Education Act, but their school does not seem to mind if we exceed a fortnight.
In the three weeks they were in Australia, I am sure they learnt as much as they would have done in the classroom. Sometimes they can be persuaded to keep diaries and to write up their experiences and, when they do, these journals provide a delightful record of the trip.
Although we often bicker and more than occasionally exchange strong words with our children, travelling with them (and we never travel without them) is always interesting and nearly always a delight. And often on our travels - just like Hello] magazine - we think about the late Princess Grace and remember Aberdovey. One day we must go back there.