Boris Johnson doesn’t like to talk about it, but he’s a bit of a fan of Ancient Greece. So he’ll be familiar with the story of Cassandra, princess of Troy, cursed to see the future but have no one believe her. The prime minister suffers from the reverse curse, where everyone around him can see what’s coming, but he refuses to believe them. (Cassandra’s curse also required her to always tell the truth. Johnson’s, again, is along similar lines, but subtly different.)

So it was that possibly the only person in Britain surprised by the prime minister’s announcement of Lockdown 3: Lockdown With a Vengeance was the prime minister. But then Johnson seems to be always the last to know what’s happening with this virus.

If it seemed like only yesterday that the PM was assuring us that schools should open, it’s because it was

It is only a month since he was telling MPs that their constituencies could be looking at looser restrictions in mid-December. It is less than a month since he was giving the country five days off for Christmas. It is just over two weeks since he announced, literally as people were packing their bags and preparing to carry their infections back to the places of their birth, that he’d had second thoughts about this. As it happens, two weeks is about how long it usually takes for infections to feed through into hospital admissions, which now turn out to be rising alarmingly.

And if it seemed like only yesterday that the prime minister was assuring us that schools should open, it’s because, well, it was only yesterday. But let’s face it, no one outside the government was planning on that staying true for long. Teachers knew it. Parents knew it. Children knew it. You really had to be in the Cabinet not to know it.

Johnson’s tone as he addressed the nation wasn’t “grave”, exactly. He so often seems to be playing the role of prime minister, the most hideous miscasting of the role since Stephen Fry led Britain through a season of “24”. On this occasion he was playing it in an under-rehearsed BBC drama from 1985 about a nuclear war. His hair was slightly subdued, like a haystack after a sudden shower.

“The whole nation has been engaged in a great national effort,” he began. Mainly this effort has been to try to comply with government rules that change from hour to hour.

Thoughts and prayers, for instance, are with all the teachers who spent their Christmas holidays trying to work out how to transform their schools into giant testing centres, because Gavin Williamson was going to threaten to take them to court if they didn’t reopen, only to be told, at 12 hours’ notice, that they should have spent their Christmas holidays planning online lessons.

These days the prime minister must borrow credibility from elsewhere

Johnson tried to suggest that things would be better organised this time around, and indeed there are signs that the government is, slowly, learning to drive around the massive traps marked “trap”, rather than repeatedly plunging straight into them: this time, free school meals will be continued without Marcus Rashford having to write any of his polite letters. But even this isn’t all good news. Teachers who weren’t already reaching for hard liquor at the start of the statement will have been driven to it by the news that Williamson and Ofqual will be working together to find a solution to the problems of cancelled exams.

“There is one huge difference compared to last year,” Johnson explained, and we waited to find out where Dominic Cummings would take his eye test this time. He turned out to be talking about vaccinations. He wanted to share with us something he referred to as “the NHS’s Realistic Expectation”. I very much hope this is one of a series of numbers the health service produces, alongside an Unrealistic Hope, a Plausible Fear, and a Ridiculous Guess. Perhaps, though, this was just an acknowledgement that these days the prime minister must borrow credibility from elsewhere.

So mid-February is the latest target date for things to start to get better. “I really do believe that we are entering the last phase of the struggle,” he told us. This was met with understandable scepticism. But one of these days he’ll be right. One of these days, it will turn out to have been the last time he had to say that. And then we’ll have to face James Cleverly and a dozen lesser government loyalists parading through studios telling us that everyone said it would be impossible for Johnson to end lockdown before November 2038, but look, he’s done it, and that just goes to show what a winner he is.

As with Cassandra, Boris is cursed. And as with Cassandra, the whole nation has to suffer it.