Bob volunteered to perform a parachute jump for charity. On his first day of training, the instructor made an important point about preparing for landing at 300 feet.
“How do you know when you’re at 300 feet?” Bob asked.
“A good question,” replied the instructor. “At 300 feet you can recognize the faces of people on the ground.”
Bob thought about this for awhile, then asked, “What happens if there’s no one there I know?”