What is ironic about the expression "Health consists of having the same diseases as one's neighbors"?
Irony is a rhetorical device that demonstrates the discrepancy between what is true and what appears to be true. The true definition of health consists of a body functioning at peak efficiency in the absence of disease. However, health is often measured by comparing the patient's level of dysfunction to the average level of dysfunction in the general population. In a population where disease is extremely common, having an average level of health could mean that one is still quite sick. Thus the appearance of health from a statistical standpoint differs drastically from the true definition.