HSBC has its own radio station. Standing in line at the agency counter in the Fenchurch Street branch, waiting to pick up cheques to be cleared by other banks, I used to listen to piped muzak interspersed with financial advice and adverts: ‘That was Abba with Money Money Money, and have you thought of an HSBC high interest savings bond for yours?’ Banks have a habit of creating these artificial worlds, homogeneous commercial hubs strung out across London.

The cheques I’d pick up on these occasions would be taken to other banks, where they’d be processed later that day. In the pre-digital age, when the Bank of England had a troop of liveried messengers to deliver cheques from bank to bank, and legions of clerks to tally up the totals, the sense of financial markets as human systems was much more obvious. On rainy days the messengers would dally in coffee shops, and the banks couldn’t sign off on their accounts. The delay meant that interest rates would be slightly adjusted, going up in case a large cheque came in at the end of the day once the weather had cleared up.

This bizarre feedback loop ended with the establishment in 1990 of the Central Moneymarkets Office after a messenger was robbed in the street of £292 million in bearer securities. The £30 billion or so that whizzes round the city every day now does so mainly through wires rather than on pieces of paper. Nevertheless I often wondered, as I cycled between Fenchurch Street and Portland Square, what would happen if I was significantly delayed (stopped by the police, say) or, worse still, lost the package. A slight ripple in the markets, perhaps? In reality probably nothing but inconvenience for the banks – but the sack for me.