Fred asked Joan, "Would you lend me $2? I want to buy a lottery scratch-off. I'll pay you back tomorrow." She said, "Sure. Just remember me if you win something." He bought a scratch-off. He used a dime to reveal the hidden numbers and symbols. He said, "Holy cow! Look at this!" He had won $1,000. She said, "Good for you!" The next day, Fred paid Joan back her $2. She said, "You said you'd remember me if you won something." He said, "No, I didn't. All I said was I'd pay you back your $2. I didn't promise you part of any winnings." She said, "If I hadn't lent you $2, you wouldn't have won anything. Don't you think you owe me half of your winnings?" He asked, "What if the scratch-off had been a loser? Then I would have owed you only a dollar—half of my losings?"