An old joke tells about a man walking home from work one day when he saw a snail on his porch. The man said, "Oooh, a snail," and he kicked it as hard as he could—sending the snail to his neighbor's yard.
Two years later, that same man was sitting in his front room watching television, when he heard a knock at the door. He answered the door—finding no one there.
As he was about to close the door, he looked down and saw that same snail from two years ago. The snail looked up and said, "So what was that all about???"
Sometimes, we go to great lengths to maintain a grudge.