re: Learning
We might get hit by a meteorite but chances are much higher to get hit by a small enough meteorite so that a whole city can be wiped out but not the entire civilization. That way we'll learn what to do.
As for human related disasters, the same should also apply. Maybe an attack can occure and many casualties would be the consequence, but then we'll learn too. It happened after WW2.
Or environmental disasters will also shift our habits.
Of course, this applies if humans recognize their responsability and don't involve an unquestioned allmighty entity.