I am not my job. In fact I bear a marginal and shoddy resemblance to my job, often to the great pain of my colleagues and superiors. I point this out because it appears that David, does.
Now, I always knew that. Which is not to say he is wholly defined by his job, just very majorly. I'm also not saying this is in fact a bad thing. He has a good job, when he is occasionally allowed to do it, and he avoids letting other people re-define him by their impressions of his work. This is a modern take on the job definition of self, and certainly I think a healthier one. Recognizing that in spite of the malignement of misguided direction, one's work has value, is very important in this gestalt.
I am not defined by my disease. I am constantly exposed to people who do this, and in fact exist in close proximity to a person who's entire definition of self is composed of a complicated (and occasionally wrong) impression of the aspects of several illnesses. Many of these are long term and incurable. As someone who has an incurable (if well controlled and relatively common, as well as treated) condition, it would be easy to allow this to happen.
I am defined by three major roles - Husband, Father, Gamer. An occasional dash of son, though my parents and I are not so close as some. I realise this only because of the effort I will spend to mix these things successfully, and because of the torment which an imbalance of these three aspects can/will bring.