You are walking about 25 feet behind a stranger who has headphones in and you notice something fall out of their pocket; you go and pick up and try to get their attention, but they get in a car and leave. Upon review, you realize that what fell out of their pocket was a winning lottery ticket.
You yourself, are in deep, deep debt and can barely feed yourself, and in real danger of being homeless. Would you keep the ticket or try to find the stranger?
The ticket is for a $600 million dollar jackpot and the stranger forgot to check number on the ticket and thus didn't sign the back of it.
For this scenario, the stranger never noticed you were walking behind them and it was only you two around (no one else saw pick up the ticket)