Submitted by cellardoor85, who says:

As special educator, I work with a 7 year old boy who has memorised the complete Berlin S-/U-Bahn, bus and tram network. Every day, he draws exactly one section of the network (without any mistakes, of course) and gives it to me as a present. Last month I started to puzzle all the parts together into one big map on the wall of my office. The common project is not finished yet, but I encouraged him to pay more attention to the west part of Berlin 😉

I am impressed; I am very, very impressed. I’d definitely love to see this again when it’s finished!