Becoming a London taxi driver isn’t as easy as you may think. Unlike other London folk who choose to take the tube or bus, taxi drivers have to spend hours learning the city’s road network for a face-to-face exam at the Public Carriage Office to get a licence to start their careers. Recent brain scans on a group of taxi drivers revealed that areas of their brains associated with memory were more developed than would be normal for the general population. So all that learning not only makes them money, but also increases their memory power.