Once while riding the bus to work, I noticed a man at a stop enjoying a cup of coffee. As we approached the stop, he finished drinking and set the cup on the ground. This negligence surprised me, since it seemed to be a good ceramic cup.
Days later I saw the same man again drinking his coffee at the bus stop. Once again, he placed the cup on the grass before boarding. When the bus pulled away, I looked back in time to see a dog carefully carrying the cup in his mouth as he headed for home.