Self-doubt is a concept that has rarely troubled Kwasi Kwarteng.
"Don't worry, I'm sure you'll do very well," the teenage Etonian joked to an apologetic admissions tutor, who had turned up late for his interview at Trinity College, Cambridge.
With supreme confidence in his intellectual abilities, Mr Kwarteng went on to dazzle audiences across the worlds of academia and politics with his mastery of multiple subjects.
"He wears it extremely heavily," says his old Cambridge university friend Dr Catherine Brown.
"But in a way that is extremely charming," she adds.
One theme stands out in Mr Kwarteng's career as an academic and now at the height of politics - this is a man who always challenges established thinking.
"I think he is certainly someone who is not going to be afraid of a big idea - he is not risk averse," says the journalist Sarah Sands who has known the chancellor since he was at Cambridge.
In Friday's statement to Parliament on his growth plan, the chancellor will slay orthodox Treasury thinking. He will cut taxes with no corresponding spending cuts - all to be funded by increased borrowing.
The Institute for Fiscal Studies says reversing the rise in National Insurance contributions and cutting corporation tax amounts to the biggest tax cut in one event since 1988.
This is a chancellor moving at speed after a relatively slow start to his political career.
Mr Kwarteng was first elected to Parliament in 2010 and saw other contemporaries shoot ahead of him up the ministerial ladder.
But one event and two people turned round his political fortunes. He was a genuine supporter of Brexit, believing with his historical overview that it was always going to happen.
"We were always going to leave," he told friends after the referendum as he moved into the new political mainstream.
"It just happened a little earlier than expected."
Mr Kwarteng was a supporter of Boris Johnson who put him on the ministerial fast-track as energy minister in 2019.
Then his political partnership with Liz Truss, a fellow member of the 2010 intake of MPs, paid dividends when she asked her close ally to serve as chancellor.
George Freeman, another member of the 2010 intake, believes that this mini-budget marks a historically significant step.
Mr Freeman, who worked under Mr Kwarteng as a business minister, told BBC Newsnight: "I think it is bold, confident stuff.
"And I think both the prime minister and Kwasi understand that leading in these roles is about confidence, the markets' confidence, public confidence in the economy.
"But it is also quite high risk and I don't think they would demur from that. I think they've understood that slow growth, post-pandemic risk of recession requires bold action."
Independent or ideologue
As an historian, it is little surprise that history instilled in Mr Kwarteng the belief of taking risks.
A key influence in his thinking about how to act as chancellor was an essay written by the economist John Maynard Keynes on Andrew Bonar Law, chancellor during World War One and later prime minister.
Mr Keynes wrote that Mr Bonar Law was highly accomplished in using his skills as a chess player to prevent political opponents from from going no more than a few moves ahead.
Mr Kwarteng saw that as a missed opportunity. Surely better, he thought, to show some flare and deploy the most idiosyncratic piece on the board - the knight.
"Kwasi is a flare of exciting, original thinking," Mr Freeman says.
"I think he's probably the most exciting appointment of this reshuffle."
But the veteran former Labour minister, Dame Margaret Hodge, believes the chancellor is embarking on a gamble too far.
Dame Margaret told Newsnight: "I think he's an ideologue who lives in a bubble, who really doesn't understand most ordinary people's lives, who has this sort of theoretical brilliance, but a total lack of pragmatism, which I think creates this chaotic set of policies.
"I can't think how anybody can believe that it is sensible at this time to reintroduce bankers bonuses when everybody else is struggling.
"I mean it's not bold, it's immoral."
Dame Margaret's remarks show Labour believes that the Kwarteng/Truss approach has gifted them a strong line of attack: Tories prioritising tax cuts that will benefit the better off.
Mr Kwarteng is unlikely to be troubled by Labour criticism.
One of his oldest friends from Cambridge, who is on the Labour left, says Mr Kwarteng never concedes an inch in political debates and mocks her views. But it always done with charm and a laugh.
"There is a political gulf of a Homeric scale between us and yet our friendship bridges it," says Dr Catherine Brown, now an English literature academic.
And his response to her political views? "Yeah, he made fun of them."
But Mr Kwarteng once found himself in a minority round Dr Brown's dinner table, prompting a revealing insight into the historian's view of Brexit.
"I think he was the only Brexiteer round this table, which was a table of academics, and he was asked to say something about his position and in defence of his position.
"He actually likened it to the English Reformation. He said that at the time Henry VIII brought that about, Henry didn't know exactly what a Protestant England or Britain was going to look like, nor did his immediate descendants.
"And it took about a century of bloodshed. These are his words. But in the end, it all worked out and Britain sailed on into its glorious future, which I thought was an interesting analogy."
As Mr Kwarteng embarks on an economic experiment he will need results on a rather faster timetable.
And he will need those to show that his decision to override Treasury orthodoxy, by cutting taxes now, has delivered strong economic growth.