I have nice stuff, but I've visited people with more. Once I was at a friend's house who was the proud owner of lots of beautiful stuff collected from all over. I looked around and said, "You might as well just have crap." He was not thrilled with that observation, but honestly, presentation is important. (OK, it isn't easy to be my friend; I'm outspoken) If lovely belongings are piled all over the place with random bits (bills, advertisements, whatever), it is difficult to bask in the glow of possession. We collect things that interest us, things we feel an attachment to. But if we don't have a clean surface for display, it is not as easy to smile when we see them.
Fortunately, my husband doesn't collect old tractors. I don't know how we could display them, although I've seen people with very tidy collections of old farming implements. I'm also glad he doesn't collect old cars for their parts:)