What is the purpose of David Cameron? What would you hire him for? Absolutely first class son-in-law material, obviously, decent tennis partner, topping fellow to have a snifter with. All of that. But does he have a useful function in the world of work?

That was the question that MPs on the Treasury and Public Accounts Committees were trying to answer on Thursday as they heard from the man who is still, somehow, amazingly, not the worst Tory prime minister this century.

Cameron was explaining his involvement in the Great Greensill Disaster, a scandal that no one in Westminster fully understands, and that, it turns out, he didn’t either. “I have no special insight into what ultimately happened,” he explained at the outset.

Four hours later, when he wound up, it was hard to argue with that analysis. He hadn’t realised the company was in trouble until the end of last year, certainly not at the point earlier in 2020 when he was banging calls and texts into every government minister he knew, and several he didn’t, seeking help. Cynics have suggested that he’s misleading us about this, and that he must have been aware. But Cameron is scarily plausible as the man who wasn’t there.

He was in the financial accounts, of course. “I was paid an annual amount,” he said. “A generous annual amount, far more than I received as prime minister. I had shares. I absolutely had a big economic investment in the future of Greensill.”

He declined to say what the generous annual amount was. It is, after all, terribly vulgar to talk about money. He seems to have got even posher since leaving office. Perhaps it’s the result of not having to hang around with the sort of low-class types one finds in the parliamentary Conservative Party.

He was a little hazy on his duties for Greensill. He was an adviser, he said. And he attended board meetings. He thought he was making an important contribution to the company. That, not the four private jets, was the thing that had attracted him, he said. He “wanted to get stuck in and help a business grow”.

But somehow, when the business was in danger of very much not growing, Cameron didn’t notice.

MPs were incredulous about this. Cameron explained how he kept in touch with what was happening at the firm that was paying him his generous annual amount: “I listened every week to the, sort of, company podcast that was describing how the company was going.” A podcast a week, eh? If that’s not worth a generous annual amount, what is?

This is a man who, wishing to know the identity of the Deputy Governor of the Bank of England, texted the Permanent Secretary of the Treasury to ask

Maybe he thought it was free money, that they were paying him just because he deserved to be paid money. Why not, after all? He decided to be prime minister because he thought he’d be good at it. (It would be polite to say opinion is divided on that question, but also wrong.) Perhaps this is what a chap gets from going to Eton: a sense of entitlement so powerful that you never question why people are giving you things. This would explain a few things about the current prime minister.

It wasn’t just recent events at Greensill that baffled Cameron. Things that happened while he was prime minister also seem to have been a bit of a mystery. Asked how Lex Greensill, the company’s founder, had come to be working for him in Downing Street, he began, “I’ve sort-of pieced this together from some of the press reports.” That sounds bad, of course, until you remember that Boris Johnson has had to commission an inquiry to find out who paid for his own wallpaper.

If Cameron never worked out what his role was at Greensill, it was pretty clear to the rest of us. His telephone-number salary was justified by the names in his contacts book. Angela Eagle suggested his frantic texting of ministers and officials was “more like stalking than lobbying”. Cameron agreed that, with hindsight, it would have been much better to write a formal letter. This is, of course, the way that a properly-brought up young gentleman ought to carry out his lobbying, but it is not, one suspects, what Greensill expected to get in return for his generous annual amount.

As a former prime minister, Cameron was in a class of his own as a lobbyist. This is a man who, wishing to know the identity of the Deputy Governor of the Bank of England, texted the Permanent Secretary of the Treasury to ask – somehow simultaneously the most and least impressive method of seeking information ever seen in the smartphone era.

Being involved in a company that collapsed was, Cameron sighed, “very depressing”. Some guys, he seemed to be saying, just never seem to catch a break.

Except that Cameron is a man who has caught every break since birth. He’s enjoyed every benefit that money and connection could deliver. And when things have gone wrong, as they do seem to have done rather a lot, he’s moved onwards, blissfully unaffected by the chaos, failing as only an Englishman of the very first rank can.

There’ll be another job after this one, similarly generous at a level which it would be vulgar to discuss. And another after that.

Had he really, he was asked early on, not noticed any hints that things were going badly wrong in the place where he apparently worked? He replied with words that so perfectly described the immense carelessness with which he governed that they should be chiselled on his tombstone: “There was certainly no sense of jeopardy.”

Reader, I believed him.