Drunken Ramblings

Chen Dawen, who loves alcohol, insists on drinking a whole bottle each time. One day, he got drunk again and his wife complained that he had finished an entire bottle of wine. Chen Dawen, with slightly blurred vision, picked up an empty bottle and shook his head, saying, "A half-empty bottle of wine is seen as half-empty by pessimists, but optimists see it as half-full. Therefore,

1/2 bottle of wine = 1/2 bottle of empty space.

Multiplying both sides by 2, we get

1 bottle of wine = 1 bottle of empty space.

So, doesn't that mean I haven't actually drunk any wine?"