I think artists are naturally kind of packrats. It might originate, in college, when you have to live on a tight budget and you never know when you might need some scrap material for a project.
Art teachers are even worse. We have that same instinct to keep potentially useful materials, like other artists, but then also know that their budget could be cut at any moment, meaning that we may have to make due with whatever we have.
This past Spring I (And by "I" I mean a student helper) cleaned out my supply closet. It was full of three or four instructor's worth of stuff. We found things in there, that predate the building. I "liberated" quite a bit of materials . You can only kid yourself so long in regards to, "I could maybe use that someday...".
A funny bit about cleaning out the closet, I had three or four prepackaged, probably pretty costly at one time, Art History sets. They consisted of a record, a cassette, and an ordered slide carousel. My guess is, you went through the slides as the record played music for ambiance and the cassette described the artwork. It was like a virtual museum tour. Anyway, after finding the sets, I had to explain to my student helper what slides were. I ended up tossing most the sets. I kept a few slides for some darkroom special effects, and gave the records to the student, which she melted to make bowls for her graduation party. Wasn't much point in keeping them, as I can look up any artwork on Google, and stream it to my digital projector...