So this, it seems to me, is what's happened: almost everybody on the official and orderly side of politics got it massively, massively wrong. The list bears repeating: the bookies, the markets, the major party leaderships, the polls. Even Nigel Farage briefly thought remain had pipped it.
So personally I knew Brexit was possible. It's become a cliche to talk about "anti-establishment feeling." The point is, I knew it was possible, but never really believed it could happen. To put that assumption in context: someone of my generation has never seen a vote defy the advice of the establishment (or at least the bulk of it).
Well, now it's happened, but with the backing of the radical right and a rump of the Tory old guard. Outside of London everywhere in England has voted to leave the EU.
Nobody knew before Brexit what would happen if there was a Brexit. Astonishingly, after the fact, we know even less. But there's a few things we can predict and have to prepare for.
Firstly, and most pressingly, Britain's foreign born, migrant, and refugee residents and citizens: they will need solidarity and a sense of security. We must cede no ground to the anti immigrant right - that might be unpopular but it's absolutely crucial.
Secondly, when the negotiations begin, the left needs to press for every social protection it can, preferably with a clearly articulated alternative of its own. My feeling is the Tories will want to avoid an election, Cameron could still somehow remain PM. Not that it matters: there is no soft option here and we can't leave it to them to decide Britain's future. We need to challenge the shit jobs, low productivity, low investment, stagnant free market economy the Tories - Brexiters and Bremainers - have built and will continue to build. This means mobilising from below. Don't mourn - organise. It's what we should have been doing all along.
Thirdly, the political party stuff: Cameron's leadership might be under threat, but (contra the Lexit nonsense) the very most we'll get is a change of personality. Expect the Right to cohere around free market nationalism. The real damage may be to Labour's radical left leadership. If we can (and I'm not sure we can) we need to protect Corbyn and keep him in position. Corbyn's euro scepticism could serve him well - or he could be jettisoned pretty swiftly. It's too early to well. As far as we can we need to redirect anger from the current leadership onto the neoliberals, the ones who allowed Labour's traditional vote to move so far from it, offered them promises about immigration and then broke those promises continually, while neoliberalism itself hacked away at their living standards.
We need an alternative to what John McDonnell calls "Tory Brexit" - but that alternative needs to be electoral and it can only come from the present Labour leadership. If the radical leadership goes (which is now a real possibility), we'll have to change tack. Corbyn could be unseated; the English electorate could align definitively with Ukip; Scotland could very easily leave the UK. All of these scenarios are possible or likely - but none are as yet inevitable. Right now there is everything to fight for.
Most of all we need to remain loudly pro-immigration. Post-Brexit, immigration almost certainly won't fall. We need to be honest about our support for immigration and firm in pointing out the lies of the Brexiters and the promises they will now inevitably break. Then we can start to offer an alternative: a more interventionist state which will use investment to regenerate Britain's flagging regional economies and channel immigration to where it's needed.
The situation has changed, but this referendum was never our vote. Either way the right and racism was always going to win. The enemy remains the same - if a little bolder. We will remain internationalists, in solidarity with our friends and comrades in Europe and beyond, whatever the treaties or deals between our states say. So once again: don't mourn - organise.