“WE ARE sorry you are leaving us. . .”. The automated message pings back to your inbox as you unsubscribe to a trail of unwanted advertisements. There is, of course, no real person at the other end. No one is sorry; no one will miss you. All you have done is to spare yourself a bit of bother.

For some, Britain’s leaving of the EU should be as simple as that: a political decision requiring little more than formal regret on the other side. The discovery that real emotions are involved comes as a shock.

This discovery is hard for both sides, in Britain and for our European neighbours. All are vulnerable to group emotions, and, currently, these are not being handled well. We are discovering that leaving the EU is not just a matter of crunching the numbers on trade and migrants to squeeze the best deal (or no deal), but a loss of relationship which is as great as any bereavement.

The griefs triggered on both sides of the debate and in Europe go back to the Second World War. Many of us in Britain are still obsessed with the war — “When Britain stood alone” — and simply feel superior to our European neighbours, convinced that our democracy is more robust and that our courage and enterprise are greater.

It is no surprise that ardent Brexiteers see our departure in terms of a conflict, even war, with the EU. It is either victory or surrender. But, on the other side, many of us still feel that leaving Europe is a kind of amputation. Cutting ourselves off at Calais is not freedom, but diminution. The fear that we feel is not “Project Fear”, but the other side of a love for mainland neighbours, and a genuine concern about the durability of European peace.

We cannot afford to take this lightly. After all, we went to war in 1939 to contend for the freedom of other nation states as well as our own. We can see that we have contributed much to the EU, and want to do more.

Our European neighbours, meanwhile, are tempted to see us as “perfidious Albion”, remembering how, as EU members, we have sometimes sulked in the shadows, paying our dues with reluctance and endlessly sniping in ways intended to undermine.

We know, in other areas of life, that the exposure of our own vulnerability is deeply disturbing, and often makes us lash out as a defence against pain. As we reflect on our forthcoming divorce from the EU, the emotional agenda that we have created by the Brexit vote is not being attended to. Plenty of emotion is being expressed, of course, much of it vehemently, but it is not being processed. Things are likely to get messier.