Ah, the Parable of the Dagger. Most people wouldn't be surprised if, when looking into a shed with word "S * * T" written on it in large letters, they'd see a s

Ah, the Parable of the Dagger. Most people wouldn't be surprised if, when looking into a shed with word "S * * T" written on it in large letters, they'd see a shovel, a garden rake, a couple of empty buckets, and a broken wheelbarrow but no feces. Yet, write "This shed is full of manure. The previous sentence and this sentence either are both true, or both false" on the shed, and they apparently will be surprised to find garden tools inside.