London is not a good place for fans of right angles. People who like the methodical grid system of Manhattan will whimper and cry at the baffling knot of streets of England’s capital. In this bewildering network, it’s entirely possible to take two right turns and end up in the same place. Or in Narnia. Even with a map, some people manage to get lost. And yet, there are thousands of Londoners who have committed the city’s entire layout to memory – cab drivers.

Piloting London’s distinctive black cabs (taxis to everyone else) is no easy feat. To earn the privilege, drivers have to pass an intense intellectual ordeal, known charmingly as The Knowledge. Ever since 1865, they’ve had to