Many model railroaders assume the red line is the approach to happiness. Bigger is better.
Others insist that only a large complex layout allows them to attain happiness. They ride the blue line.
Some people are never really happy regardless of what they build. Those are the yellow line folks.
I suspect that most of us in the real world of commitments other than hobbies walk the green line. Yes, a layout can be too big.
While you contemplate this, enjoy this cover rendition of the popular song "Happy" by the Canadian Group Walk Off the Earth and Parachute.