When I got out of the Army and went to college, I lived in perhaps one of the smallest row houses in Philly, only 9.5 feet wide. My desire to build was strong and while I was on a very strict budget, I nonetheless built a 3' x 4' O-gauge train layout using O-27 track. Later, I built 2' x 4' modules.
The "groove" that I've been in the last decade or so has been one of continuously wanting to build nicer scenes that complement the detailed O-scale trains. I bet many of you can relate to this. We see these magnificent locomotives and cars and desire to build layout scenery & operations for them to run and operate through. The "name of the game" is having fun, and the craft of our hobby doesn't have to be expensive.