There was this guy, and he cared about the environment. He never threw mostly-empty paint cans in the trash when he was finished with a painting project. “Paint is bad for the environment,” he said. “It goes in the landfill, it ends up in the groundwater.” So he put his old paint cans in the shed to await the day when he could carry them to the paint disposal place across town.
All his friends said, “Listen—all you’ve got to do is to throw your old paint cans in the trash, put some garbage on top. The trash men will carry them right off. They’ll never know the difference.”
The guy said, “You like drinking paint, do you?”
“Pardon?” his friends said.
“You like drinking paint? That’s what you’ll be doing if everybody throws their paint cans in the trash. It gets in the groundwater, you know.” His friends went away chastened.