Boris Johnson’s 772-page doorstop of a memoir, Unleashed, recounts a chequered political career in his familiar boosterish tone. Here are five things we learned (spoiler: he hasn’t learned much at all):

He’s baffled the Tories ditched him – and convinced he’d have won this year’s election

Johnson’s retelling of the “torrid sort of summer” that ended his premiership is shot through with bewilderment. While he admits to a few mistakes – not least failing to read the findings against disgraced MP Owen Paterson before publicly defending him – he essentially believes MPs were wrong to defenestrate him.

When Rishi Sunak resigned as chancellor, “it was worse than a crime, I thought, it was a mistake – both for Rishi and for the party, never mind the country. So it proved.” Johnson’s biggest failing, as he recalls it, was not buttering up Tory MPs enough. “Too often I would go back to the Number Ten flat, tired out, and work into the evening, when I should have been talking to colleagues and keeping them cheerful.” If his colleagues had “stuck together”, he has “no doubt that we would have gone on to win in 2024”.

Partygate was cooked up by Cummings and Cain

Johnson’s account of what he calls this “miserable and wildly inflated affair”, is that on about 15 occasions, officials “briefly slackened the tempo of their work and raised a glass”. A “handful” of times, he joined them.

He maintains these events were in line with Covid rules, but that his former chief of staff Dominic Cummings and his director of communications Lee Cain orchestrated a string of “grossly exaggerated” media reports in a deliberate attempt to undermine him. The pair were, he says, “behind it all”. He believes he could have ridden out the storm, if he had been “far more robust at the time”.

Elsewhere, Cummings is barely mentioned: the “trivial row” that resulted in Sajid Javid’s resignation in February 2020 was, Johnson says, “confected by people who really didn’t have my interests at heart”. The internecine wrangle that resulted in Cummings’ and Cain’s departures, in November 2020, he describes as, “handbags”.

He doesn’t regret much about the pandemic

The chapters on Covid are the most painstaking and amount to Johnson’s justification of his decision-making at every stage.

He shook hands with staff when visiting Covid patients at the Royal Free hospital because “shaking hands is an ancient human gesture of goodwill” and he didn’t want to spread undue alarm.

He stresses the patchy information available in the early days, including the false idea that asymptomatic transmission was unlikely. A moment of epiphany appears to have been when he watched footage of overwhelmed Italian hospitals – which he knew were generally good, because he had used them when his toddler fell in the pool on holiday in Umbria. There is no acknowledgment that the government could, or should, have moved faster to remove “ancient and hallowed liberties from the people”, as he puts it.

He’s a closet Keynesian

While he would never use the term, Johnson clearly believes, along with the economist John Maynard Keynes, that a good dose of government spending can help the economy weather hard times.

After the 2008 banking crisis, as mayor of London, he describes throwing his weight behind Crossrail to prevent George Osborne eyeing it up for cuts when the Tory coalition came to power in 2010. “Those big investments – Crossrail, the Olympic site, the Westfield Centre at Shepherd’s Bush – were fortuitously timed for London: vast counter-cyclical programmes that kept the spades going into the ground and people in work.”

Never a fan of “austerity”, he repeatedly praises infrastructure projects, particularly in transport. As Covid abated, he says, “we had to use this terrifying moment to our advantage … by driving on full-pelt with our investments in everything from HS2 to hospitals to broadband.” He deplores Sunak’s subsequent decision to cancel much of HS2.

He has many Serious Thoughts about foreign policy

While you may have picked up the book to read about the drama of Brexit or the shame of Partygate, Johnson wants you to know that he has considered weighty geopolitical matters.

There are chapters on Kosovo, where he was reporting for the Telegraph when Nato troops rolled in, the invasion of Iraq (“an arrogant, conceited and misbegotten adventure”), Libya and Syria, where we “really thumped Assad” when Johnson was foreign secretary – which he suggests was the most that the west could have done in the circumstances.

He repeatedly rejects the idea that Brexit has made the UK more insular, insisting that his travels as foreign secretary and prime minister convinced him that many countries around the world, “wanted more Britain, especially in the places where Britain was already well known”.

• Unleashed by Boris Johnson will be published on 10 October by William Collins (£30). To support the Guardian and Observer, pre-order your copy at guardianbookshop.com. Delivery charges may apply