"I will be sitting in the same office by 2027," the Prime Minister stated, noting that if our discussion went well, he might welcome us into Downing Street for a follow-up talk in the coming year.
There is rarely ever time off for those in the top job. Just an hour before our chat started, the PM had been speaking with Ukraine's Volodymyr Zelensky and trying to understand precisely had occurred in Venezuela, where his key friend, US President Donald Trump, had just targeted and seized its leader, Nicolás Maduro.
When the discussion, which was much longer than typical, had concluded, Maduro had been charged in New York.
With the year commences, Starmer seems to have had something of a refresh. Perhaps even just a little downtime with his family at Chequers, the prime minister's country retreat.
This appeared to have left him in better spirits than at the sluggish conclusion of 2025, a awful political year for him.
Yet, are he and his colleagues being unrealistic if they believe his fortunes are set to turn around?
The uncomfortable reality for the prime minister is that a significant number of his fellow MPs are convinced he's not very good at his job. Several of them would sooner gamble and remove him sooner rather than later.
But Sir Keir was dismissing such talk when we spoke on Saturday morning.
Repeatedly he insisted he'd be "judged at the poll", maintaining no one would remove his five-year mandate from him – even if the best chance of halting Nigel Farage and Reform UK entering No 10 may be for Labour to switch leader.
"We are in the struggle of our generation and I intend to lead us," he declared.
The challenge for the PM is that he will be assessed far sooner than then – in a major set of elections in May across the UK. He tried to argue, perhaps too much, that they are concerning who runs councils, and who runs the devolved administrations in Holyrood or Cardiff – and not about Westminster.
True – up to a point. But even though he may not want to concede it, No 10 will be judged by those elections too.
This did not stop Sir Keir implying that there were no situation under which he would resign, even if one of his MPs contested his leadership for the job, should those elections prove catastrophic for Labour.
He attempted to explain his unpopularity by saying the electorate was naturally impatient for things to change. He tried to assure the interviewer, and the nation, that this year would be distinct.
The economy would improve notwithstanding rising unemployment, he claimed, when policies the government enacted during their first choppy year began to take effect.
His big argument is that soon the country will "reach a turning point".
The PM may have communicated with more energy than I've seen from him for a some time – less tense, maybe, with more time to talk.
But despite facing pressure from various quarters for a bolder strategy, with much more political vision, more vigour, more speed and more urgency, his points were well-known ones.
Given that he is in such significant political difficulty, is a different approach required a change of tack?
No administration, and certainly not one that has been struggling in the polls for many months, gets everything its as planned.
Sir Keir's challenges are not just because governing is hard, but because he and his team have made mistakes, even in the last few weeks.
The PM told me that he regretted saying he was "delighted" to see the return of the Egyptian-British activist Alaa Abd El Fattah to the UK following an outcry when past remarks he'd made in the past – including calls for Zionists and police to be killed – resurfaced.
Starmer attributed it to "procedures" for not realising what the activist had said before – a fancier way of saying it wasn't his responsibility.
And he is inviting clear political perils as the year gets going. His friendship with the US president takes on a new complication after Trump's military action on Venezuela.
Based on years of interviewing Sir Keir Starmer, a former human rights lawyer who was against the war in Iraq, over many years, the thought he would be at ease with such action seems far-fetched.
He stated he was a "career-long proponent of international law" but the public "just do not have the full picture at the moment".
Opponents called for him to criticise the action prior to the interview. And the government is likely to face more pressure to give an definitive view in Parliament in the next few days.
There has also long been growing pressure in the Labour ranks to revisit some of the outcomes of Brexit.
Sir Keir denies he's pursuing that, but his new more concrete plan to align more closely with the EU's single market – the vast economic European trading zone – will likely trigger protests that he is going back on his pledge never to try to overturn the decisions that stemmed from Brexit.
A commitment to align with more of the single market will please some on his backbenches, but it is simple material for Reform and the Conservatives to