Imagine two survivors standing on the big walls surrounding a destroyed Troy. A: "This can't happen again. We've instructed the entire guard to not let anyone

Imagine two survivors standing on the big walls surrounding a destroyed Troy. A: "This can't happen again. We've instructed the entire guard to not let anyone pass through the gates if they are bringing giant, horse-shaped statues with them." B: "Hmm. And if they bring giant, ox-shaped statues?" A: "Nah, what are the odds someone would try that?"