This rule, as you know, says that 80% of our time is wasted, while 20% of our time actually accomplishes ?80% of our tasks. Or close to that!
But it works in other areas too. 80% of what we think is erroneous as it is based on misinformation mainly from out of date theories and science. Of the 20% that is correct, we disbelieve 80% of it, for the same reasons.
It requires effort to get it right and trawling the web and reflecting helps a lot!
(You do know that 80% of the WWW is deliberate misinformation, don't you?)