The tragedy of virtue is that the more obvious, boring, unoriginal, and sermonizing the proverb, the harder it is to implement. - Nassim Nicholas Taleb

Doctors most commonly get mixed up between absence of evidence and evidence of absence.

A complex system, contrary to what people believe, does not require complicated systems and regulations and intricate policies. The simpler, the better. Complications lead to multiplicative chains of unanticipated effects. Because of opacity, an intervention leads to unforeseen consequences, followed by apologies about the “unforeseen” aspect of the consequences, then to another intervention to correct the secondary effects, leading to an explosive series of branching “unforeseen” responses, each one worse than the preceding one. Yet simplicity has been difficult to implement in modern life because it is against the spirit of a certain brand of people who seek sophistication so they can justify their profession.

Dumb enemies are a problem as they can be very hard to predict.