Regarding, smoking and bloodletting, the former was bought and paid for by industry, that is just fraud. For the latter, there are cases where bloodletting actually works. Medieval medicine isn't the backward thinking we often ascribe to it and many would argue that it wasn't a "Dark" ages at all. There are even modern instances where maggots are the best solution for cleaning wounds. Even given that history, the recent advances by people whose jobs I can't even begin to understand, can nuke my entire immune system to treat a cancer and bring me back to full health. That is not something an autodidactic can do.