Most people's immediate thoughts, following last year's referendum, correctly focused on the situation of European citizens currently living in this country, as well as that of British citizens living in Europe. Now, however, attention has turned to the economy and jobs - exemplified by Labour's so-called 'jobs Brexit'.
Yet it is time that we reflected on a concern that has not received nearly enough attention - even though it is the most significant right that individual British citizens, and in particular young people, will lose if we leave Europe. Namely the 'right to roam' across our own continent - in other words the right to travel, work and study throughout Europe - and to do so freely and at will. This is then not just about what happens to the British already in Europe. It is about young people starting out in life, and the opportunities, too, for every future generation.
And although what is now the European Union began as a political and an economic arrangement to ensure the continent's stability after a devastating world war, this freedom to roam has become increasingly regarded as a fundamental and democratic right of European citizens - indeed affirmed as such by the 2004 Citizens' Rights Directive, and incorporated into UK law in 2006.
This is a right, moreover, which, if we lose, will continue to be enjoyed by almost every other citizen within Europe, certainly those of the 27 other EU countries, as well as the four EFTA countries, all occupying the European Economic Area, excepting Switzerland which has a separate yet analogous agreement to the Directive. The young people of Albania - even with its status as a candidate for EU membership - would have more rights of free movement within Europe than us. Despite the accusation by Brexiteers that any time soon the EU is about to fall apart, the direction of travel is towards a Europe where all young people will enjoy this right (everyone excepting the British perhaps), the only thing in practice stopping other citizens doing so being the need to prove the democratic credentials and human rights records of the few remaining European countries outside the EEA.
Outside the UK there is incredulity that British citizens are willing to give up this right. For the British, traditionally used to travelling across the world pretty much at will, it is perhaps far too easy to take things for granted in a Europe that has moved on and continues to do so. In the UK all the concern, even up to now, has been about people coming into the country - very little about ourselves travelling into Europe. Yet the opportunities to work and study abroad have opened up tremendously in recent years - the Erasmus Programme, for instance, this month celebrates its thirtieth anniversary. It is perhaps an irony that many of those older people who voted leave will themselves have children, nephews and nieces - even grandchildren - who have taken jobs abroad, if only for a few weeks in the summer. Many of those Brexiteers believed that for young people things would carry on as before, without fully realising that any deal involving movement of people is one that has to be reciprocal.
The most chilling phrase that the Conservative government has been repeating is 'attracting the brightest and the best' - code for established and well-salaried. Chilling because then all hope that ordinary young British people will continue to enjoy the current rights to work, study and travel outside the UK will be removed, as the rich and the privileged will be the only people able to cross borders with any degree of the freedom of movement enjoyed by all other ordinary Europeans.
Of course, the one European country that other Europeans won't have the free right to roam will be the UK itself. But what ordinary citizen will want to visit or work in the country that, in terms of free movement, might then become the new 'East Germany' of Europe, policing its borders and hardly allowing people in or out apart from the occasional increasingly expensive holiday? With a hard Brexit, this is not such a fanciful scenario.
What can be done? There needs to be mobilisation against the loss of this right. Many young people who found their political voice on June 8th and who voted Labour voted both against austerity and against Brexit, hoping that May's 'hard Brexit' would be countered and a debate could be opened up.
Brexit can be argued against on the basis of these principles alone. But there is also the offer that Belgian MEP Guy Verhofstadt made that any UK citizen who wished to keep an EU passport should be allowed to do so - what has been termed 'associate EU citizenship'. That should certainly be part of any deal that took us out of the EU. And when one starts to think about it who in their right mind would turn down a passport that offered so much more than the more restrictive one - at the very least a shorter queue at the other end for holiday-makers? At this point, it has to be said, the whole idea of Brexit seems to collapse like a house of cards.
Some are now arguing that some form of soft Brexit can be achieved. Although the Conservatives start in the driving seat, Jeremy Corbyn has already made it clear that he will try and protect study arrangements abroad. Nevertheless, as we enter negotiations - whoever finalises the deal - the sense is of an agreement on rights which may be significantly worse for UK nationals than those currently held by EU and EFTA citizens. The fight must be for UK citizens to have the same opportunities within Europe as all other Europeans. How can it be sane to settle for anything else, which would be a 'lesser right'? The freedom to roam is a right that needs to be fought for and defended in its totality. It cannot be compromised on - in the end this has to be the same right as that enjoyed by all the other citizens of this continent.