Human GPS Before Google Maps

What's the creepiest display of intelligence you've seen by another human? In my first job

in Australia, there was a guy named William. The first odd thing I noticed was that

he liked to program this old PDP-11 computer we had there, by toggling in machine

instructions one at a time on the front panel. He had memorized the whole instruction

set, in binary. Later, I found he knew where every postcode

in Australia was located. He had a train hobby, and apparently the postcodes followed

the train lines. Then he moved on to buses. He memorized all the bus routes in

our major cities. He had a source for getting periodic updates. We could ask him