It has been affirming, in recent weeks, to meet so many people working together, making sacrifices small and large for the “Remain” campaign. We are united of course in our bemusement at what we perceive to be what The Washington Post called the “insanity” of the Brexit case; our case feels hard, in large part, because I think it is. But when the dust has settled and tempers cooled, however, I wonder if we might better understand their apparent eccentricity by recognising some of it within ourselves.

Because, at the personal level, few of the sacrifices make obvious sense – meanwhile, some of our own ideas are sometimes too firm. Whilst it has been heart-stirring to see people stuffing envelopes and giving money and travelling across Europe to help, it can also be head-scratching, too. In Casablanca, Rick Lane’s character makes a common declaration of apparent cynicism “the lives of two little people don’t amount to a hill of beans in this crazy world” –it is echoed in politics often. Whilst voting is easy, it is still a sacrifice of time: as big a mystery as the millions voting for Brexit, are the millions voting at all.

But yet, we make sacrifices, and we like them-and the fact millions will vote conscious that it is indecisive, proves voting has a dual purpose. As I hope Casablanca fans will acknowledge, Lane’s words prove ironic– along with his declaration he will “stick his neck out for nobody”. He urges and makes a huge sacrifice that serves a wider good – but he does it for himself because he will “regret it” for the rest of his life if he does not. Whilst our cinematic reactions are bitter-sweet, we accept it because it is actually the human instinct we know best. Though the stakes are not always so high, we close gates and recycle paper cups and refrain from theft, when it would be in our interests not to, every day. As our great Whig forerunner Adam Smith argued in Theory of Moral Sentiments it is this moral eye that keeps the world moving forward, totally unseen. Though it was unclear at the time – filmed only in 1941 – the fictional idea represented the real actions of millions of un-historic acts which won WWII.

On the same basis, for all contemporary cynicism, we remain political animals, because it is in our nature to be a social species. Whilst we tend to squint at social media identity, and be cynical about the new trend of “virtue signalling”, there is another more powerful form of vanity, of which this is maybe just an extension: that which we keep for ourselves. Although self-deception is associated with a strong psyche and a good memory with a fragile one, at the end of the day, we define ourselves by our deeds, even those we hide from others: “truth is truth until the end of reckoning” – and none is harder than our own.

But this has two dangerous outputs, the first is an inflexible alluring idea. Europhiles like me can better empathise with those voters who ignore the economic case for the EU – explained by the Washington Post – if we empathise with ourselves. On Thursday I will in part vote Remain seeking to attach myself to the cosmopolitanism of Rick’s Café and memories of Paris, decayed into the pigment of my imagination: but this has proven dangerous before, as many of us who wrapped smart arguments around the Euro – a workable scheme, in too wide an area- around worthwhile archetypes. But though beauty is good, we should know when to use it well – such as to deliver thousands of “Remain” leaflets” for the logical goal of international cooperation on peace and trade – whilst also learning to recognise it when its a disguise for unreason, just as the French Minister who said “you do not leave the land of Plato waiting at the door” did not.

The second is that though we seek belonging as people, we cannot belong to everything, at least not all the time. Rick’s enemies were human’s too, and their identity to a large degree arbitrary, and so are our Brexit opponents who are – typically- shaped by different experiences to us. I hear sincerity when I hear talk of “our people” – too much of it. Though we might judge the sacrifices and intuitions of opponents wrong, some of us on the “Remain” side can empathise with the temptation to commit “nasty” acts to defend our belonging, too.

This Referendum has made identity we suspect in party politics painfully explicit. But as liberals we should be sanguine: it is fluid, and broad. Anyone can sympathise with anyone when they have enough time. More usefully, we can attain identity and social affirmation from very different things, depending on our focus. People will not want to attach to social negatives– such as Europe, from which we are physically and emotionally detached –they will feel embarrassed to endorse an “economic suicide”, if it is clear, too. Pollsters have a hard time, I think, because this kind of affirmation can only manifest at the ballot box, when we can grab it.

We all vote for different superficial reasons, but for a few moments, every few years, they make most feel good. By this selfishly selfish mechanism, both “Remain” and “Brexit” campaigns and voters certainly amount to a “hill of beans”. I am not sure this can be a coincidence, and it must somewhere lie in the fact we are a highly successful, instinctively social, species. But though we have a rational need to belong, this can lead cause us to make peculiar collective choices.

Whatever they are, we should never claim the messages are not real, or are simply “stupid”. Whilst millions will vote for Brexit for Anglo-Saxon simpatico, or because they coolly judge Brussels bureaucracy bad, millions will see Brexit as a loser’s cause, and not want to carry around that image of themselves in their head for the next generation. The degree to which the Remain campaign can make clear the latter – and the paucity of evidence of exit for Leave – will determine the result; but the motivations will have something in common. The outcome will do a lot to define the country’s future – but you cannot assume people exclusively voting on that basis: they will do so to define the world, but also themselves.

* Douglas Oliver is secretary of the Liberal Democrat History Group and is based in London.