In Extremistan environments a Gaussian distribution is used at your peril.
improbable
improbable.
Extreme events do happen and have a big effect.
Taleb argues that the proposition "we know" is in many cases an illusion—the human mind tends to think it knows, but it does not always have a solid basis for this delusion of "I know". This notion that we do not know is very old, dated as far back at least as Socrates.
Socrates' dictum "the only thing I know is that I do not know"