In November 2015, Ursula Burns was on her morning training walk around Central Park in New York when she learnt that Carl Icahn, one of the most notorious US corporate activists, had taken a 7.1 per cent stake in Xerox.

The next few days were a blur, says Ms Burns, who had worked her way up from engineering intern to chief executive of the venerable technology and services company. Mr Icahn’s call for change at Xerox was a challenge not only to her strategy but to the organisation where she had spent more than half her life.

“I took it personally,” she recalls. But the straight-talking chief executive also received some important advice about how to cope: do not take it personally. Without that wise counsel to treat the approach dispassionately, “everything would have turned out very differently,” she says.