QUOTE : If you visit London, you’ll occasionally cross paths with young men (and less often women) on motor scooters, blithely darting in and out of traffic while studying maps affixed to their handlebars. These studious cyclists are training to become London cabdrivers. Before they can receive accreditation from London’s Public Carriage Office, cabbies-in-training must spend two to four years memorizing the locations and traffic patterns of all 25,000 streets in the vast and vastly confusing city, as well as the locations of 1,400 landmarks. Their training culminates in an infamously daunting exam called “the Knowledge,” in which they not only have to plot the shortest route between any two points in the metropolitan area, but also name important places of interest along the way. Only about three out of ten people who train for the Knowledge obtain certification.