John McDonnell, shadow chancellor in the Corbynite splinter-group, has announced that £120 billion is waiting to be reclaimed from tax avoidance, evasion and other schemes. Nero was equally detached from reality.

The Roman historian Tacitus tells us that in ad 65 a fantasist from Carthage by name of Caesellius Bassus bribed his way into an interview with Nero and told him that on his estate there was hidden a vast quantity of gold, not in coin but in unworked bullion — great columns of it. It had been hidden there, he said, by Dido, the Phoenician queen who had founded Carthage.

Nero was thrilled. Triremes filled with soldiers and rowed by top oarsmen were immediately dispatched, and the escapade was the talk of the town, the general populace utterly convinced, the sensible taking an alternative view. Sycophantic orators praised the emperor, announcing that earth had invented a new form of fruitfulness, and this windfall must surely signal divine intervention.

Nero’s extravagance blossomed on these idle hopes, says Tacitus, and resources were squandered as though they were now guaranteed for years to come; free handouts to the people multiplied, resulting in further national impoverishment. Meanwhile Caesellius Bassus, followed by the soldiers and hordes of locals commissioned to do the work, having excavated all his own land to no effect, extended operations over a wide area around it, asserting that one or another location had to be the site. Eventually forced to admit defeat, he expressed amazement that, up till then, his dreams had always turned out to be true, and this was the first that had ever let him down. Tacitus ends the story by saying that he was briefly imprisoned, released and had all his property confiscated to compensate for ‘Dido’s treasure’.

Don’t give up on your fantasies, John. Keep on digging. There’s treasure buried there somewhere, for sure.