I am an OCD, endorphin junkie, weight weenie, so what ever you do don't read any farther if you want a rational answer.
To me, it is 100% of both. I can't stop tweaking the bike and the more I tweak it the more I look at it and the more I look at it the more I want to ride it. Would I find excuses to not ride as much as I do if it didn't excite me sitting still? Maybe, maybe not. I know I feel great after pushing myself hard for 20 miles after work, but I also know that sometimes it is tough to get on the bike. Looks like rain, the couch and TV look so inviting, etc. I think the more excited the bike gets you the more you want to ride, and it is really all about the ride. All about the ride? Didn't I just say it is all about the bike? I'm out of here. The bike is calling me right now.
Good luck, Greg