"Beijing was such a different city," says Ma Jun, China's preeminent environmental watchdog, remembering the capital as it was during his childhood. "There were so few cars, I could walk in the middle of the road. In the summer, the streetlamps attracted swirling bugs. I loved those bugs: crickets, ...

But this practice usually fades as we become adults. Our houses become filled with our own “stuff.” Garages, attics, basements, and closets transform into cluttered warehouses. When we need something, whether it’s a chainsaw or a roasting rack, our first thought is to go out and buy it. But why get ...