We are all supposed to remember where we were when we heard that Mrs Thatcher had resigned (my mother rang me while I was having a late breakfast). But I will always have a much more vivid memory of where I was when I heard Boris Johnson had called it a day. I was at a mountain refuge in Andorra when a Dutch hiker told me: ‘I’ve just spoken to my wife and she tells me your Boris Johnson has resigned.’ It turned out to be four days after the actual event. Between Boris appearing at his Downing Street lectern and me hearing about it I had managed to walk 100 miles across three countries, scale nearly a Mount Everest-worth of mountain passes and survive in my skimpy tent the foulest thunderstorm I have ever known.

To be about the last Briton to find out that the Prime Minister had quit is perhaps a bit embarrassing for someone who writes about politics. But there is something inside me that rather enjoyed being a latter-day Hiroo Onoda – the last Japanese soldier to find out that the second world war was over, surrendering on an island in the Philippines in 1974. Thanks to smartphones, holidays are no longer sanctuaries from the 24-hour news cycle. The blissful news blackout of a plane flight is being eroded as airlines start to relax a ban on mobile phones.

Even so, I managed to find the perfect place to take a sojourn from 2022. Several months ago, I reached one of those milestones in life which you can’t ignore: I became old enough to move into sheltered accommodation. I thought I would mark the occasion by strapping on a backpack and walking the 500 miles of the Haute Route de la Pyrenées, from Hendaye on the French Atlantic coast to Banyuls-sur-Mer on the Mediterranean, taking in the highest peaks in between. This is a trip I had long wanted to do, but just lacked the time.

It is not a light undertaking. There is 150,000 feet of ascent along the way, much of it over boulders and paths of splintered granite. It is a province mostly of lone men with makeshift beards who can be seen skulking in the very occasional café, demolishing croissants as if it is their first meal in days – and it probably is.

Unless you know how to field-dress a marmot, finding the calories to keep going is as big a challenge as slithering up the slushy snow which overlays the fragmented glacier of Aneto, the highest peak. Once you have passed a Spanish convenience store freshly shuttered for its long siesta, it can be a four-day hike to the next one. The saving grace are the mountain refuges. They combine the dormitories of Dotheboys Hall and third-world sanitation with surprisingly good food, although I hate to think of the carbon emissions involved in helicoptering salads to a hut at 2,000 metres.

The challenge lies in trying to get the weight of your backpack down to the bare minimum, to the point I discarded any books, cut my maps in half and dumped my normal tent for a pricey but super-light bivvy bag which left me, during the thunderstorm, with an unfortunate choice: leave it unzipped and get wet or zip it up and suffocate. I met one hiker along the way who had managed to lose the sole pair of underpants he had brought on the trip – and, hurrying to a small Spanish town about to settle into its eight-hour siesta, could only find women’s knickers to replace them.

But oh, the isolation. For days I found myself tramping through zero-bar country, two or three mountain passes a day, each three or four thousand feet high, with no connection to the outside world. Until, that is, I made a discovery: it was often possible to get a mobile phone signal just at the top of the peaks. From then on, the spell was broken and I found it hard to resist trying to follow the Tory leadership election, obtaining an update at each summit.

Even a few days away from the news seems to destroy one’s judgment. The night after I heard of the PM’s resignation, I awoke shivering at 5 a.m. as a rime of frost built up on the outside of my tent (it’s a different world at 2,400 metres, even in a scorching July). No, it couldn’t be Rishi Sunak, I reasoned – the business of his wife’s non-dom status had fatally damaged him. Liz Truss? No, far too shrill – Tory MPs would see she would frighten the voters and never win an election. At that hour, all logic seemed to point to Sajid Javid – who, I learned by the time I had trod the scree to reach the summit of the 2,900m Puig Carlit, had been eliminated without even enough MPs to back his candidature.

When I arrived on the Med, 28 days after leaving Hendaye, I was fully back in touch with the news from Blighty. I learned that Britain was about to suffer a 40°C heatwave, which according to the Met Office meant it wouldn’t be safe to go outside. And as if that wasn’t bad enough, I read on the BBC that south-western France was apparently in the grip of a ‘heat apocalypse’ – which, although it had been hot, touching 37°C in the afternoon, came as a slight surprise given that I had just hiked 25 miles, passing numerous other unparched people on the way and failed to spot a single one of the wildfires which had apparently consumed huge swaths of the country (although I did pass through some smoke outside Bordeaux on the train home).

Back to the world of news. It is fun, as ever, to be plugged back into our 24-hour media. But I have to say there are times I pine for my four weeks spent largely oblivious to it all.