I can't understand how you can't understand this. How can someone of normal intelligence not understand that many things contain or are made out of water theref

I can't understand how you can't understand this. How can someone of normal intelligence not understand that many things contain or are made out of water therefore the person saying that meant he/she doesn't drink pure water. He/she probably drinks juice. This is so obvious. How can a person of normal intelligence not be aware of this? Perhaps such a person is aware... he's just being human and like all humans sometimes does things that are harmless and slightly illogical.