Do you ever picture a specific place when you think of LEGO? Something idealized or nostalgic that makes building more exciting for you, personally.
Whenever I think of old System sets from 2006 and earlier, I always come back to the mental image of a small, cozy living room during the winter. Incandescent lights, carpeted floor, wooden furniture - just the kind of place I was at when I was young and first got into LEGO. It might sound weird, maybe pretentions, but I find that the ambience around you can be an important factor when you're delving into your imagination.