The truth matters, doesn't it?
In what's meant to be a grown-up Western democracy surely we'd all like to think so. It doesn't pay to be naïve. Politicians, even really honest ones, regularly say things they don't quite believe.
The public knows this. We don't expect our politicians to be angels. But outright lying, in my experience, is relatively rare. It is too easily found out.
Only one senior politician still in the game has ever privately told me something that was utterly, entirely, and completely untrue. It was proved publicly to be a lie a few days later.
It's also rare for opposition parties to accuse a prime minister, on the record, of lying.
Which brings us to Boris Johnson.
The prime minister's relationship with the truth is under intense scrutiny at the moment. He is refusing to give full explanations on some issues. There are questions about how the refurbishment of his Downing Street flat was initially funded, and about incendiary comments he made last autumn as England was about to enter a second lockdown.
Downing Street is repeatedly denying that he has done anything wrong.
It is not the first time in Boris Johnson's long career that he has faced questions about his conduct and character. But the stakes are so much higher now. His unique way of running things - and sometimes chaotic approach to decision-making - has, sources tell me, led exasperated colleagues in No 10 to nickname him "Trolley".
"You think you are pushing it along a path towards your goal then suddenly it veers off disastrously," says one insider.
If anyone wanted to submit accurate Freedom of Information requests on government WhatsApp messages, "you'd have to include the trolley emoji", adds my source. No 10 declined to comment on the name.
It was Mr Johnson himself who may have coined the analogy, telling friends he was "veering all over the place like a shopping trolley," over whether to back Leave or Remain, ahead of the Brexit referendum, according to the Sunday Times. He famously wrote two versions of his newspaper column, one backing Leave, the other Remain, arguing through all the options to be completely sure.
Some of his allies cite this desire to argue things backwards and forwards before reaching a decision as a strength, saying: "He challenges organisations and conventional wisdom."
Others have a more straightforward explanation.
"He is just sometimes unable to face the truth because he doesn't like making hard decisions," says one insider. Another says: "You are never sure what the real truth of a situation is." Others say it is hard to get clarity and a sense of purpose, or that it is "hard to work out where his motives begin and end".
So what does this tell us about the prime minister's relationship with the truth?
First, the benign interpretation of how the PM operates. One insider who knows him well says it is simply "unfair and easy to cry 'liar', as the opposition has done".
"He's far more complex and strategic and people don't give him credit for how calculating and clever he is."
Another source told me Mr Johnson has a "genuinely selective memory" and that "'I choose to remember certain things or not remember others'" is his default way of dealing with the pressures of life at No 10.
For years, it's been the case that when things get sticky, particularly with Boris Johnson's personal life or financial affairs, he refuses to engage in those conversations at all, even in private with his close aides. The message to staffers is, effectively: "Don't ask, because I won't tell."
One source told me that is why, right now, life in No 10 is bound to be tense and difficult.
"Part of the problem is that these two things, his personal relationships and his financial situation are colliding. He'll be finding it very difficult, and people trying to advise him will also find that hard."
But is he not telling the truth?
This particular source believes that the PM may try to evade questions about matters of the home and heart, but not on political issues.
"To a degree every politician has to go out and say things they don't always agree with. He is a professional and he does that."
There's another layer when it comes to Mr Johnson though. And discussing his habits with many of those who have worked alongside him, his former life as a journalist is often mentioned.
Strategy to bamboozle
Even his worst enemy would acknowledge that he is a skilled wordsmith, and he regularly uses his vast range of sometimes nonsensical vocabulary to deflect, to entertain, or even ridicule. It's certainly not unusual for politicians to try to avoid answering questions that would cast them or their parties in a less than flattering light.
One of the PM's strategies, however, seems to be to bamboozle the listener with a blizzard of verbiage, suggesting agreement, but not committing to anything. Former colleagues suggest that by the time they have decoded what he actually meant, the conversation's over.
An insider told me: "He frequently leaves people with the belief that he has told them one thing, but he has given himself room for manoeuvre," believing that, "the fewer cast iron positions you hold the better, because you can always change political direction."
The verbal flourishes and rhetorical tricks are part of the reason why he has prospered.
"A lot of his magic has been those off-the-cuff comments, that's why a lot of the public like him," says an ally.
He was like an "untamed political animal" when he first developed his political style says another, playing with phrases as he would in his byzantine and flamboyant newspaper columns, teasing with words, presenting a character like no other politician.
But another told me it has developed into a way of shrouding what's really going on.
"I think he is an extremely shrewd and calculating character that hides it all under the costume of a performer," says this source.
One Brexiteer even suggests his mannerisms encourage others to be complicit: "It's like a comedian, you are willing him on, you want it to be plausible" - even if, according to them, it simply isn't.
That's where his personal style, according to others, tips into something much less appealing. A former minister, once close to him, told me: "The problem is that it's becoming clearer that the PM treats facts like he treats all his relationships - utterly disposable once inconvenient.
"It's all about power. Facts, policies, people - they all get ditched if they get in the way. Whatever is necessary."
Like Steve Jobs
Yet what's suggested time and again is that the prime minister's attitude to the truth and facts is not based on what is real and what is not, but is driven by what he wants to achieve in that moment - what he desires, rather than what he believes. And there is no question, that approach, coupled with an intense force of personality can be enormously effective.
In his political career, Boris Johnson has time and again overturned the odds, and that's a huge part of the reason why.
One former colleague compares him to the late Steve Jobs, the hard-driving founder of tech giant Apple. Jobs was said to have a "reality distortion field", described by his biographer as a "confounding melange of a charismatic rhetorical style, indomitable will, and eagerness to bend any fact to fit the purpose at hand".
In other words, ordering the truth to suit his ambitions, refusing to take no for an answer, relishing proving that the impossible could be done.
Mr Johnson's former colleague told me: "Is there wilful lying? I would struggle to point to a direct example. Does he recreate the truth to suit him? Yes."
This source, and several others, told me the prime minister has a "deep dislike of being accused of lying". Several sources have even suggested that during the 2016 Brexit campaign he was nervous about the now infamous promise, plastered on the side of his battle bus, to spend the £350m a week the UK sends to the EU "to fund the NHS instead".
Mr Johnson was conscious that every time he used this claim, it could be challenged by the fact that the £350m did not take into account the budget rebate the UK got from the EU.
Mr Johnson was all about "images, emotions, he didn't want to be pinned down to a number", says my source.
He was also understood to be unhappy about the campaign's claims about Turkey's proposed entry to the EU, and the potential impact on immigration. If you're reading this, you probably don't need a reminder of how controversial those claims were at the time. Just in case, you can read about them here and here.
But private doubts about whether the claims were convincing did not stop Mr Johnson from becoming the biggest cheerleader for leaving the EU. The rest, of course, is history.
Some of those with him on the Brexit journey don't think that he was ever a true believer.
A veteran Brexiteer told me: "Boris is not one of us, but we put him there - and that is a truth he is never going to want to confront."
Big trouble ahead?
Forgetting the recent history, does any of this actually matter politically now? Voters don't generally consider politicians to be particularly trustworthy.
Boris Johnson's reputation and popularity is certainly not based on a view that he tells the truth, the whole truth, and nothing but. He has what pollsters call "authenticity" - what you see is what you get. He's not super smooth and he doesn't pretend to be perfect.
The current allegations about his conduct, which he characteristically describes as a "farrago of nonsense" do not seem to be shifting public opinion much, if at all.
But just because the Conservatives can shout loudly that no one cares about this stuff, that doesn't mean that the prime minister's complicated relationship with truth can be easily dismissed. Most straightforwardly, there are several investigations now into exactly what has happened with the Downing Street flat that could trip up him and the Conservative Party.
Sources who told the BBC and other news organisations that Mr Johnson did say he would rather see "bodies pile high" than take the country into a third lockdown have said they would be prepared to testify under oath if they have to.
Depending how and when those two issues unwind, there could be big trouble for Downing Street.
Politics is an extremely tough business, as Mr Johnson has been discovering of late. Huge parliamentary majorities do not protect you from personal criticism. And many of the government's current woes can, arguably, be traced back to the PM's relationship with the truth.
I've been told on more occasions than I can count that Boris Johnson trusts hardly anyone, and suspects almost everyone. As one source describes it, he "behaves in such a way that people eventually tire of him, feel let down, and behave in the way he feared they would". The breakdown in his relationship with his former adviser Dominic Cummings is spectacular evidence of that.
But people who work alongside Mr Johnson are often kept guessing, unsure of what he really thinks.
It leaves him all powerful. His whim rules.
But it also can make it harder to achieve what he says he wants - the priorities he was elected to deliver.
Yet popularity matters in politics too. Despite the horrors of coronavirus, hard realities have never been part of the PM's desired script. To use one of his tactics, quoting the classics, the Greek philosopher Plato said: "No one is more hated than he who speaks the truth."
But as one of the few people who genuinely knows Boris Johnson once told me, he is a politician who above all, wants to be loved.