There’s a good reason why doctors have difficulties with rare diseases—which is, of course, the rarity itself.

> In medical school, aspiring doctors spend a few minutes at most on these relatively unusual conditions.

It would be unethical to spend a lot of time studying these conditions while many more people suffer from the more frequent ones.

Sooner than later, we’ll be able to solve, say, depression reliably via pills or vaccines or whatever, and then more rare diseases will be studied much better (likewise, there was little point in spending much time on depression when smallpox was around).