Every Postman Pat is a cartographer too

Yesterday I worked a little extra, delivering the scarce Monday post for a number of postcodes areas that on a normal day would be divided up in 4 or 5 individual rounds. I'd never walked any of these rounds before, but I know all the streets well and some of them were right next to the street that I live in. But as the post covered quite a large part of the neighbourhood the more experienced colleague at the depot drew me a map from memory to explain the route. I don't know if it's clear if you don't know the place but this is a wonderful example of how deep knowledge of a terrain is part of the job. The mental cartographic skills involved are extraordinary: it plots the most efficient route (the product of years of experience), frames the area using the railway and the roundabout,  points out landmarks and key addresses, shows the street grid with rare accuracy and completely ignores all the bits of information that I didn't need. The street in the middle almost crosses the street left of it at a 180 degree angle, but you wouldn't see it here. The dozen streets in between are missing too. Conceptually this map has the clarity of the London Tube map. Big up to Pat!