5. Structures as Scenery
Structures are structures, and scenery is scenery, right? Yes, there's a distinction between them with respect to their origins: structures are manmade, and scenery is natural. But in terms of a layout, both are really just visual elements—stage props surrounding the actors (trains). Buildings convey certain information in order to create a setting, and this is really no different from the role of trees and rocks and water.
To be sure, I didn't arrive at this in a sudden revelation; it's come to me gradually over the decades I've been modeling. But I'd pretty much become cognizant of it by the time I started building this layout: I was looking at everything in terms of the feeling conveyed. Nowadays, I treat every object on a layout as a visual element designed to support a core visual theme (or, as I prefer to call it, the "mood").
I regret not finishing the layout, but I've always maintained that "it's the journey, not the destination," and this journey taught me a great deal that no other layout ever had.