Not so long ago, a middle-aged patient came to my office for a checkup. He cheerfully admitted that he hadn't been paying attention to his diabetes for the last few years. He'd stopped taking his medicine, stopped seeing his doctors, stopped thinking about the disease altogether. When I checked his blood sugar in the office, it wasn't just a little elevated — it was four times the normal level. For doctors, it is always a shocker to hear a case like this. How can a patient completely ignore a disease for so long? How can a life-threatening illness just disappear from someone's consciousness?