I DID not, in the event, “bung a bob for a Big Ben bong”, as our Prime Minister recommended everyone should do, so that the nation’s most iconic clock could be temporarily restored to chime at 11 tonight, to mark the UK’s departure from the European Union. But you have to hand it to Boris: he has a good alliterative ear for a memorable meaty metaphor.

This one was perhaps more fitting than he realised. The Big Ben Brexit Bong sounded like a good idea, but turned out to be impossible to implement for both practical and legal reasons. It would have been too costly: halting the current restoration work on the clock would have cost £500,000. Public donations to pay for it were inconsistent with the “principles of propriety and proper oversight of public expenditure” of the rules of the House of Commons — not that such niceties have troubled Mr Johnson overmuch in the past.

But the striking of a bell, as distinct from the tolling of one, appealed to many Brexiteers. It signalled the “clean break” that they had craved. It would show that they had succeeded in “getting Brexit done”. It was a symbol of change, like a New Year resolution or giving up drink for January.

The reality is different. Brexit is a process rather than an event, as the opening salvoes, fired by the EU’s chief negotiator, Michel Barnier, have this week shown. At least a year of negotiations lie ahead. Eleven o’clock tonight, with or without bongs, is not the end. It is not even the beginning of the end. It is just the end of the beginning, as Mr Johnson’s hero Winston Churchill put it.

Still, the Big Bong Moment has provoked some interesting philosophical reflections. Professor Diarmaid MacCulloch is to give a lecture next month at the Religion Media Centre, offering a narrative of the United Kingdom as an exclusively Protestant story, with the Reformation uniting the previously irreconcilable kingdoms of Scotland and England. Mark Hudson, writing in The Tablet, offered a more Catholic vision, encompassing Greek philosophy, 1000 years of Christendom, the Enlightenment, and the pan-European tradition of social democracy. Others remembered Dean Acheson’s classic judgement from the 1960s that Britain had “lost an empire and has not yet found a role”.

And yet the 1960s were a period of such economic affluence that the decline of the Empire went largely unnoticed. The run-up to Brexit, in contrast, was a period of such economic austerity that the past became gilded with the memory of days when Britain was Great.

“Getting out of the Empire barely scratched the national psyche,” that most perceptive of contemporary historians, Lord Hennessy, observed. “Brexit has scored us deeply.” It may yet do so more profoundly, especially if Brexit pushes Scotland to independence and Ireland to reunification.

It was left to the inaptly named Mark François, the buccaneering Brexiteer ad absurdum, to communicate to Bong enthusiasts what happens when ideology encounters reality. The £270,000 donated by members of the public towards the £500,000 cost of putting the clock back would instead be donated to the veterans’ charity Help For Heroes. Heroes speak of glory, greatness, and the golden age. But they pay the cost with broken limbs and wounded minds.