Daimler has given frazzled employees the opportunity to delete automatically all emails received while they are on holiday. The carmaker’s move underlines what everyone already knows: personal technology can abrade the self. Finding several thousand unread messages makes one’s first day back at work peculiarly horrible.

This is not the fault of device makers, social networks or mobile data operators. It is a consequence of our determination, fed by professional and personal paranoia, to use all their products and services at once. The malady’s symptoms are a fractured attention span, insomnia triggered by exposure to blue light and an ever wider, shallower friendship group.

I spotted a typical sufferer last month on a train rolling through Concord, Massachusetts, home of Henry David Thoreau, a nature philosopher who believed that in 1840s America: “The incessant anxiety and strain of some is a well-nigh incurable form of disease.” True to that diagnosis, our contemporary victim was tetchily switching between mobile phones as bandwidth fluctuated. He was also juggling an iPad and a pager. He was organising a business trip to Indianapolis. He should have alighted at Concord and thrown his devices in Walden Pond, the lake where Thoreau swam after retreating from modern life.