Today is garbage-pickup day for those in my neighborhood who choose to have a truck swing by and collect their trash. Barrels and boxes dot the sidewalk in front of some houses. There are no such containers in front of my house -- I take the garbage to the dump myself.
This morning, as I looked out front, I noticed a variety of trash bits in front of my house ... a tin-foil container, some balled-up newspaper, and a few odd chunks of cardboard. Apparently they had blown into my world from someone else's world and I decided to collect them after the rain let up.
But twenty minutes later, when I returned to the porch, my across-the-street neighbor was out in front of my house, red umbrella in hand, dog in tow, picking up the trash she evidently recognized as her own. She returned them to the trash barrels in front of her house.
Now that's what I call a sensible person -- someone who takes responsibility for and makes the effort on behalf of their own leavings. Everyone leaves a trail in one way or another, but I see no reason not to do your best.