Great point! For me it is a combination of a couple of things, laziness, yes, but also an overwhelming sense of things to do when I finally get time to head down to the train room. As a solution, I have stated to make lists of small projects that I can complete in a few "sessions" in the train room. I find that if I can focus down on a small area of scenery or weathering a couple of cars, or building a structure, I can eliminate the sense of the walls closing in on me and actually replace it with a feeling of accomplishment and satisfaction!
Scott