Do you ever look at an empty box and go "that's a nice looking box. Better not throw that out. That'll come in handy some day". You don't know what you're gonna use it for yet but it's there just in case.
What I tend to do at work is think to myself "I'll be good and get rid of all these empty boxes and ditch the clutter", and then 48 hours later be turning the place upside down trying to find a box to ship something to one of our other sites in.
I have been known to keep the really hard ones that come with wrapping paper. If you get a coat hanger and mold it you can can slip a dusting glove onto the wire and bend it, attach it to the tube, you can dust things higher up without getting on a chair.