By learning to live on (and love) the edge of chaos.
No, that's too easy. Avoiding jumping to conclusions is a prerequisite for learning, and for many unusual diagnoses, no?
A favourite of mine: in my (brief) days as a medical student, I worked in a rural hospital, including a Leprosy unit - in which 'feeling no pain' is the key evidence for the disease (nerve degeneration leads to loss of sensation), which is why it is missed so often by doctors who don't normally see cases of Leprosy, and 'can't imagine' why NOT feeling pain would ever be a key symptom for disease.
So ... the rarer it is, the more difficult it is to diagnose.
