I never thought of it as having a collection, it's just that my layout isn't big enough to run everything I have so those not currently selected to run are collecting dust on various shelves or sit in the dark of storage cabinets waiting for their chance at the high rail.
I suspect that many, if not most of the people participating on this board have more trains than they can fit on their layout.
And most people who fish have lots of tackle.
And many people who like to work on cars have all sorts of tools.
I think there is a little bit of the collector in many of us, whether or not we like to admit it. 
