How quickly they are forgotten. Only this week, Boris Johnson – go on, you must remember him – was excised from pictorial history.

It was hard not to laugh. His erstwhile colleague, Grant Shapps, posted a picture of a previous Ministerial visit to Spaceport Cornwall, as it prepared for the first rocket launch from UK soil.

Turned out the pic had been doctored. To remove Boris. It would seem that, Orwell style, he is now a non-person. Mr Shapps vigorously denied responsibility for the editing.

Still, it might give others ideas. Keir Starmer might prefer it if the voters forgot that he previously worked alongside Jeremy Corbyn.

And then there is Nicola Sturgeon. Perhaps, if she gave the matter some thought, she could identify a former SNP leader she would rather not hear from again.

Read more by Brian TaylorA way back for the Scottish Tories? Mibbes aye, mibbes…

The episode was a reminder of the transience of politics. And of its trials and tribulations. (The rocket launch failed.)

But some things seem constant. Nicola Sturgeon still yearns for a referendum on independence.

Rishi Sunak, whom she met in Inverness, still says now is not the time, that the focus should be upon other matters.

Incidentally, it was even suggested that Mr Sunak had a mild degree of photo phobia, that he was relieved to avoid the customary awkward pic on the steps of Bute House.

Probably had more to do with scheduling. But, still, it helped emphasise that the talks were chatty and constructive. Less like a State visit – from a Union state Ms Sturgeon seeks to leave.

To be clear, the Prime Minister is not saying never to indyref2. Indeed, in a BBC Scotland wireless interview, he said three times that it was not to be contemplated “right now.”

The Herald: A Glasgow Yes marchA Glasgow Yes march (Image: NQ)

To which Ms Sturgeon replies that it should not be his call, that she has a mandate to hold a further referendum, particularly in the light of Brexit.

Indeed, that message was underlined at Holyrood this week when Angus Robertson successfully moved a motion that the people of Scotland had a sovereign right to determine their governance.

I was intrigued by the tone of the argument deployed by Mr Robertson, the Constitution Secretary.

He linked independence to Brexit, arguing that Scottish views were being ignored. So much, so familiar. But he also argued that those who endorsed the Union in 2014 were promised economic gains, which had not materialised.

Again, familiar. Except that the tone was more one of flight, of escape than has been the case in the past, when the SNP argued that Scotland should have the confidence to endorse full self-government.

I have noticed the word “escape” being deployed by SNP politicians recently when talking about constitutional relationships on these islands.

No big deal. But a change of tone.

So where next? There is a special conference of the SNP on the 19th of March when members will discuss strategy.

READ MORE BY BRIAN TAYLOR: Supreme Court is a challenge for Sturgeon – and Sunak

It follows the ruling by the UK Supreme Court that the Scottish Parliament cannot instigate a formal referendum, that this remains a matter reserved to Westminster under the 1998 Act which established devolution.

This weekend, the party’s NEC is expected to outline a draft agenda for that special strategy conference.

I am told that it will be neither prescriptive nor proscriptive. Rather, it will leave ample room for amendments and for discussion.

From Ms Sturgeon’s point of view, that is eminently sensible.

She set out her own thoughts – that the next UK general election, expected next year, should be, as far as Scotland is concerned, a de facto referendum.

However, the party she leads is decidedly uneasy. That much is evident from conversations with senior Nationalists.

This is not remotely a simplistic “split” in the Nationalist movement. It is much more nuanced than that. Nevertheless, there is disquiet.

Frankly, nobody in the party wanted to be in this position. It is not Plan B. More Plan F. But, as one senior figure put it to me, “the alternative is giving up – and we are by no means ready to do that.”

The mood is still uncertain – and therefore the outcome is, to some extent, unpredictable.

However, it is possible to discern a series of threads emerging from the discussions which are taking place in SNP circles across Scotland.

Firstly, there are very few who would advocate anything other than a formal, statutory referendum. Nobody in the SNP wants to emulate Catalunya where an unsanctioned plebiscite is thought to have set back the Catalan cause.

Secondly, there had been some talk of a mass resignation at Holyrood, rather than focusing upon the Westminster election. That notion seems to have very little traction. One told me it was “for the birds”.

But the Westminster idea also has detractors. Consider this. The parties supporting the Union will decline to play. They will say the UK General Election should be just that: electing MPs and thus the next government of the UK.

They will spend the whole campaign denigrating the SNP and their “de facto” referendum.

But what if the SNP fall short of their self-imposed target of 50 per cent of the popular vote – bearing in mind they have never reached that level in electoral history?

Why then, say SNP sceptics, the Unionists would argue that the people have spoken, that independence has been rejected again. As one put it to me, the cry would be: you’ll have had your referendum.

So, is there an alternative approach? Perhaps, some suggest, the party should link a different demand to that Westminster contest.

Perhaps the SNP should press for the transfer of further constitutional powers to Holyrood. Specifically, the power to hold a statutory referendum, to address the Supreme Court ruling.

An interesting thought, perhaps lessening risk. But does it not also come up against the same quandary? What happens when the Prime Minister says no, when Westminster says no?

Another senior party figure told me that the SNP must simply be prepared for a prolonged campaign, building up momentum, slowly and steadily.

Rishi Sunak, meanwhile, will seek to stress the advantages of Union as he sees them, through economic co-operation, such as over the new green freeports.

Picture, PM? Much obliged.