A friend of mine, who studied at one of the best colleges in one of the best universities at the world, thinks that Brexit is so complex that to fully understand it is beyond the comprehension of any one person.
Given that he studied alongside, or was taught by, some of the smartest people on the planet, that is quite a statement.
He was exaggerating perhaps, given that there are people who can recite pi from memory to 20,000+ digits, but not by much.
Brexit is sufficiently complicated that even experts are undecided on some of the details, and it is one reason why Brexit developments can pass by under the radar.
I often phone highly informed people with a query about a detail relating to the implications of a proposal with regard to an aspect of Brexit and their answer might begin along the lines of: “I’m not sure but I suspect that ...”
Different areas of knowledge are required to have a proper grasp of Brexit, such as trade policy or constitutional law or economics.
This has meant that there is sharp disagreement on the implications of, for example, Northern Ireland staying in the EU customs union unlike the rest of the UK.
Some experts say it would not matter much and others say that it is of paramount importance.
Some of the complexity of Brexit was apparent yesterday in the letter that Theresa May sent to the DUP leader Arlene Foster and her deputy Nigel Dodds.
There were almost opposing interpretations of what it meant.
The distinguished economist Graham Gudgin, for example, is pro Brexit but yesterday was relaxed about suggested increased regulatory convergence between Northern Ireland and the EU as referred to in the prime minister’s letter.
Some observers said that the letter left open the option of a so-called ‘backstop to the backstop’ while others said that it in fact reflected Theresa May’s resistance to such a clause.
The backstop to the backstop is most easily be summarised as an attempt to ensure that safeguards for the EU ensuring no hard Irish land border are permanent. It would, in effect, ensure NI was always in the EU customs and regulatory space.
Latterly there have been suggestions that the prime minister might agree it on the basis that it would never need to come into effect.
On that crucial topic, in her letter to the DUP, Mrs May wrote: “As you know, the EU ... want to maintain a Northern Ireland only ‘backstop to the backstop’ in case the future negotiations are unsuccessful. I am clear that I could not accept there being any circumstances or conditions in which that ‘backstop to the backstop’, which would break up the UK customs territory, could come in to force.
“That is why it is critical that the provision for a UK-EU joint customs territory is legally binding in the Withdrawal Agreement itself, so that no ‘backstop to a backstop’ is required.”
That strikes me as a carefully worded set of two paragraphs.
When Mrs May says that she would not accept circumstances in which a ‘backstop to the backstop’ would come into force, is she saying that she will nonetheless agree it as text on the basis that it will not be needed? When she says that she wants the agreement to be binding so that the backstop to the backstop is not required, does she mean not required as in not included in the legal text, or not required as in not ever needing to be activated?
I fear the latter, given this daft talk of agreeing a backstop that cannot be used. If it can never be used then why on earth agree it (unless in fact you are agreeing something that you know the EU demands because it might well be used)?
When I asked Nigel Dodds this yesterday, when interviewing him for his response to the letter, he was not sure what exactly was meant by those ambiguous two paragraphs.
Imagine the reverse happening. Imagine the EU, desperate for a deal (as the UK clearly is), agreeing to a legal provision that the UK was insisting upon, but something its citizens in the EU and Ireland would not like, and then trying to say it was only agreeing the point in a way that would ensure the UK would never be able to use the provision.
It isn’t easy to imagine, is it?
Mr Dodds was confident yesterday that if the prime minister was indeed going to fold fully on the backstop, with the ultimate impact of an Irish Sea border, the government would not get such a Brexit deal past the House of Commons.
There would not be enough Labour MPs who might vote for such an agreement to counter to the Brexiteer, Scottish Tories and DUP MPs who would vote against it.
• Ben Lowry (@BenLowry2) is News Letter deputy editor