What David Mundell needs to learn is that his inability to comprehend something doesn't necessarily make it "odd". The problem may well not be with the concept that is perplexing him, but with his own intellectual capacities.
Mundell's comments suggest that he makes no distinction between the UK and the EU. Both are political unions. Therefore, to his evidently limited way of thinking, they are the same. Thus, he is left utterly confused by the notion that people might want to end one political union, but preserve the other.
This is not a problem for people who understand the nature of the EU and the UK. But, like other British nationalists, Mundell has no idea what the UK is. He doesn't understand it,because he has never questioned it. He has never even thought about it. His attachment to the British state is more instinctive and emotional than intellectual and pragmatic.
This is why the anti-independence campaign was no more than that - an entirely negative anti-independence campaign. There was no pro-union campaign. There could be no positive case for the union because, in order to formulate such a case, unionists would have had to reflect on the question of what the union is. And they simply can't do that.
I doubt if Mundell has any better idea of what the EU is. So it is, perhaps, unsurprising that he can so easily fall into the simplistic folly of equating it with the UK. So, the SNP's position of independence in Europe is bound to be incomprehensible to the poor soul.
He is not alone. Many people make the same mistake. Those on the Yes side in Scotland's constitutional debate are generally people who have questioned the whole concept of the political union between Scotland and England. They are the ones who have scrutinised this constitutional arrangement. And they have found it to be profoundly unsatisfactory.
Yes voters are people who think for themselves. They get behind the propaganda and beyond the sentiment and they look at the reality of the union. Pretty much everybody who does this ends up supporting the restoration of Scotland's rightful constitutional status.
The lever that moves No voters away from their unthinking attachment to the British state is the question that prompts them to start thinking about it. That may well be a different question for each. There is no one 'magic question' that will do the trick. But once the barrier of blind allegiance is breached, the process is self-fulfilling. And there is rarely any going back. Once the illusion is broken, the structures of power, privilege and patronage which define the British state cannot be unseen.
The political union between Scotland and England is an arrangement that we, the people, had no part in creating or sanctioning. It is an anachronistic, disfunctional, corrupt union which serves none of the people off these islands well.
It is a union which was always intended to serve the purposes of the ruling elites. A union which, in that regard if no other, has not changed one iota in the last three centuries.
It is a union that sucks the human and material resources out of our nation and in return gives us government by parties that we have emphatically rejected at the polls.
It is a union that imposes policies which are anathema to our people. Policies which have been rejected by our democratically elected representatives.
It is a union which, were we being given that option now, not one of us would vote to join.
For all Mundell's inability to appreciate the fact, there is no meaningful similarity between the UK and the EU. For all its defects - and there are many - it is a modern, democratic organisation. Not perfectly democratic. But the perfectly democratic organisation doesn't exist.
The EU is, in its essence, a bold and largely successful experiment in post-imperial international arrangements. Politicians and bureaucrats may have buggered-up bits of it. But the fundamental idea is sound. Far more sound than the underpinning concept of the UK - which is, basically, just the latest formulation of the 'Greater England' project.
Seeing things as they are dispels confusion. Scotland is a nation. The EU is an association of nations. The UK is more like a cartel dominated by an entrenched clique.
All we seek for Scotland is the right to freely negotiate the terms on which our nation associates with others - be that England, the EU, or any other nation or international organisation. British nationalists are determined to deny us this right. The EU does not. That, if nothing else, is a difference that should be apparent even to a blinkered, dogma-bound unionist ideologue like David Mundell.