This is often misconstrued.

80% of sales come from 20% of the customers > yes, fire the customers who bring in 80% of the work.

80% of goals come from 20% of the players > no, your formation should not change everyone to forwards

Opportunities come 80% from networking, 20% from working hard > if you spend all your time networking, people would avoid you

Very often there's a support structure in place which leads to to the results.