I realized a while ago I have a form of OCD, full blown and out of control I would be a hoarder. Luckily for me it comes in the form of collecting, has since I was a child. Star Wars figures. He-Man figures. Music CD's. Vidoe games. Knives. Guns. Every few years I tend to shift focus. Now with the new house and money tight I am in trouble, as I can't free wheel spend like I used to. I've explained to my wife that its a driving need, without adding something, somewhere to "the collection" I get depressed and moody. She advised seeing a shrink, to whit I countered that is is a hell of a lot cheaper to buy a CD, pocket knife, etc... every now and again than paying to see a shrink.
I've gotten better at the frequency in which I need to buy, and I've been real good at choosing items which don't cost much. But I guess that's where my "collection" comes from. All users at one time or another, parred down to my favorites I keep in rotation.