There’s a pervasive belief in this society that perfection is possible. So if something bad occurs, it can never be because we just got unlucky. It must be because something went wrong and someone is at fault, and then things must be fixed. Sometimes, though, this simply isn’t true. Sometimes it’s better not to fix things: either there is no fix, or the fix is more expensive than living with the problem, or the side effects of the fix are worse than the problem. And sometimes you can do everything right and have it still turn out wrong. Welcome to the real world.

Bruce Schneier, “David Brooks on Resilience in the Face of Security Imperfection”