You probably don't live in London, then:

http://en.wikipedia.org/wiki/Taxicabs_of_the_United_Kingdom#...

When taxi drivers are required to demonstrate a deep knowledge of the geography of their area and are not allowed to rely on maps or GPS navigation systems in order to be certified, you end up with taxi drivers that are very good at navigating the city.

Now, you're adding a very strong element of filtering to the process, and you can't really make any statements about how big of a component of the ability to navigate is learned.