What is the 80/20 rule

Every now and then someone will reference the 80/20 rule, in conversation or in a video or something, and they will always dutifully explain what it means, but I’m pretty sure whenever they start explaining it I black out and my brain does this:

So here are a few of the explanations I have come up with to try to keep up whenever anyone mentions the 80/20 rule:

80% of the work takes 20% of the effort 

80% of the work takes 20% of the time

The last 20% of the work takes 80% of the time

The first 20% of the work takes 80% of the time

80% of the work requires 20% of the knowledge

80% of the knowledge gets you to 20% of the work 

80% of the work is figuring out what 20% is 

80% of a given project is 20% of a larger project 

20% of effort is 80% of the point

The last 20% of anything doesn’t matter

The last 80% of anything doesn’t matter 

80% of 20% is something 

But 20% of 80% is nothing

80% of ducks are actually geese

20% of geese are actually cranes