My office is starting to be overwhelmed with stuff. When I first got back into art, I was rubber stamping, and I accrued a large collection of stamps and supplies. Some of those things are still useful since I made many of my own background papers to stamp on.
Then I started collaging (and buying cool paper items from ebay). I have great unused soda pop labels, maps, old books, vintage postage stamps and fabric labels. That led to some 3-D work, and collecting buttons, kitchen items, and game pieces.
To make great backgrounds for these things, I started using acrylic paint (and all the mediums: "medium", soft gel, heavy gel, tar, etc.). Then I moved to painting on canvas, which led to oil pastels and soft pastels.
It's easy to see how each of these approaches led to the accumulation of stuff. I can definitely see parting with some of it in order to keep some order and make me feel like I have enough room to change my mind in here. On the other hand, I still like all of this stuff! Maybe I'll just take over another room. Or get therapy.