In How the Mind Works (as he does with more detail and elaboration The Stuff of Thought), Steven Pinker brings up the way in which we do not (perhaps cannot) naturally conceive of our bodies as vessels.
No matter that the Church sometimes refers to Mary in this way. (Doesn't it? Or am I imagining that? Is that a dream?)
So, for example, we find it immediately odd if someone says, "I drove to school today with a gallon of blood in the car. Human blood, too."
Or, as I asked yesterday when a student got up from his chair, "How did you get all that blood off your chair?"