Just over a year ago, I jumped on a plane and flew to Davos, Switzerland, to take part in the World Economic Forum’s annual meeting. My friend (and fellow FT columnist) Rana Foroohar did the same. Shortly afterwards, we went skiing together in Massachusetts. In those innocent pre-Covid days, that sequence of events seemed unremarkable. Most global executives — and many journalists — have spent a great deal of their time whizzing around in aircraft.

Skiing on the US’s East Coast (which Rana and I have done together for years) does not normally attract attention — and certainly not envy: compared with the Swiss Alps, the hills there are low, the weather (in) famously cold and the food far worse than fondue.

But our February 2020 trip was striking: soon after our families arrived, we all succumbed to fevers, hacking coughs and breathlessness so bad that we barely made it on to the slopes. Was it Covid-19? Had we unwittingly caught it in Davos in late January, where thousands of globetrotters were crammed into small spaces for several days?