Somewhere in a parallel universe, David Cameron has lost the 2015 election. Resisting a referendum on Britain’s EU membership has cost the Conservatives their coalition majority in the Commons. Ed Miliband is Prime Minister.

In another of those universes, Cameron has won that election, and the EU referendum too. But that last victory, by 52 per cent to 48 per cent, has settled nothing. UKIP is rampant. Tory MPs are clamouring for a re-run. The Government is marooned. Cameron is under leadership challenge pressure. His most likely successor is his recently-appointed deputy, who was appointed to appease eurosceptic Party opinion: Michael Gove.

In another, Cameron fends off a challenge, but is winkled out a year later. In another still, he is forced out, and Gove begins to prepare for a referendum. In another, he hangs on – only to be beaten by John McDonnell, Labour’s new leader, in 2020.

As we time-travel back to our world, where we will find Cameron’s memoirs waiting for us, it is worth mulling the moral of these visits – namely, that Europe lays Conservative Prime Ministers low in the end. Like death, it is a matter of when, not whether. John Major, Margaret Thatcher: both perished. For Cameron, it was simply a matter of how Europe would get him. Choose your poison. Take your pick. Cameron’s was a referendum.

This is not to say that his decision to hold one was wrong. Yes, he could perhaps have faced down UKIP. Yes, he could maybe have resisted Conservative MPs without sparking a leadership ballot. And, yes, there was no overwhelming public pressure for a poll.

But referendums are now a well-established constitutional device. Cameron had won two already – on electoral reform and Scottish independence. That surprise 2015 election win may have convinced him that he could defy political gravity, and soar to victory fourth time lucky. Instead, he crashed and burned. The vote to Leave defined his legacy and bred these memoirs. Everything else is secondary.

So Cameron should not be judged harshly for providing a third plebiscite that would doubtless have come sooner or later – even if his prime motive was party management. Leavers can’t complain about him providing the referendum that we clamoured for.

Nor should they or anyone else criticise his resignation. He was damned if he went – for putting “his trotters up”, as Danny Dyer put it – and would have been damned if he didn’t, for attempting to cling to office in the face of the greatest electoral rebuff in British electoral history. No, the reason for public resentment, from Remainers and Leavers alike, lies less in the fact of the referendum than in its framing. Cameron failed in his duty to prepare for the result.

This is usually said in the context of governmental readiness for Brexit. But the truth runs deeper, and is ultimately political – bound up with the oddity that distinguished this referendum from its predecessors: that the Government wanted a No vote.

For this reason, Cameron brokered no institutional means of interpreting the result. EEA or No Deal? Or a bespoke deal instead? The Remain campaign, focused on Project Fear, and its Leave rival, fixed on taking back control, mutually failed to spot the problem. So, frankly, did this site. But unlike Cameron, we weren’t charged with governing the country. He trusted to his luck, and lost. And the unravelling parcel was passed to Theresa May.

It would be presumptuous to judge Cameron’s memoir before reading it (not that this will stop some from so doing, this very weekend). But one point leaps out from the extracts. The author has “left the truth at home” – some of it, anyway.

The phrase is one that he applies to Gove, but it could also be applied to his own account. He says he is sorry for the result of the referendum, but not for deciding to hold it. That last claim surely cannot be true. It is impossible to believe that Cameron would have pushed the referendum had he known in advance that it would pull him down. After all, he was the quintessential pragmatic power politician – consistent in tone, attitude and character.

So while he can tell the truth – that he feels that he failed, say, or that he misses office – he cannot bring himself to tell the whole truth. It would be too humiliating. It would leave him no legacy at all, save one that many have already forgotten.

Which is that he was rather a good Prime Minister – salvaging the economy, reforming public services, appointing radical Ministers: Gove, Iain Duncan Smith, May herself. His general election record as a Tory post-war winner was bettered only by Margaret Thatcher’s. But Europe swamped his boat and sunk him. Those parallel universes are just that – unreachable, unrealisable.

Perhaps there is more to the title of these memoirs than one sees at first glance. When a politician makes a statement “for the record” it is usually not so much true or false as a work of art. He is saying what he wants to say rather than what he really thinks – or maybe what he really should say. This is Cameron’s first shot at re-entry.

But the attempt comes too early. Brexit is unresolved. Memories are raw. Voters are not yet ready to lend Cameron their ears and give him a hearing. If they ever will be. One suspects that he knows it. How much better he would have done, in reputational terms, to hold his counsel, stay schtum – and publish later. After all, he is still scarcely 50.

Being a decent sort, he has held off for a time – not wanting to tread on May’s kitten heels while she was Prime Minister. But going to print was necessary sooner rather than later. So here he is, knocking on a door that is shut, and may never open again.