How does one know when one has amassed enough things? Probably never? It's a silly question, really.
I enjoy collecting interesting books with interesting covers so that they are not only interesting to read but interesting to gaze upon and talk about from a couch or chair in my living room when certain conversations with guests stray or become dull. I also take great satisfaction in creating small vignettes of books and magazines and little devices. When I grow tired of a particular scene, it's easy to rearrange things to construct a different stack of somethings or an entirely new setting.
The small number of wintry Christmas decorations I borrowed from my mother have provided new ideas, but mostly a lot of unnecessary glitter.
I am also a nail-biter, and it might be possible to equate these mindless acts of moving things as artful fidgeting. At least my cuticles aren't suffering.