People with chronic disease often make a sharp distinction between being ill and having a serious underlying problem. This distinction is more than semantic. There is substantial danger in using, as a basis for making plans, people's ideas about their feelings about contracting diseases or entering into states of disability. The discrepancies between how people with serious health problems feel about these problems and the conceptions of those who do not have serious health problems raise warning flags about how far to proceed on the basis of theoretical preconceptions. Several studies suggest that patients' actual behavior is quite different from what we might expect. They may be less willing to eschew technology than we have thought.