Joyce Redding in Reader's Digest, February, 1980
A retired couple decided that they should walk two miles a day to stay in shape. They chose to walk a mile out on a lonely country road so they would have no choice but to walk back. At the one-mile mark on their first venture, the man asked his wife, "Do you think you can make it back all right, or are you too tired?"
"Oh, no," she said. "I'm not tired. I can make it fine."
"Good," he replied. "I'll wait here. You go back, get the car and come get me."