In business, ‘no one knows anything’.
Unlike mathematics where you can prove things and build upon previous work, in business external variables change.
What ends up happening is that people can be very knowledgeable about something that doesn’t matter anymore or is less effective.
No one knows anything means.. start from scratch and reason up. See where logic takes you. If it takes you to the current place, fine. But more often than not you’ll discover that the way we’re doing X hasn’t changed or got worse compared to years ago.
So don’t download knowledge into your head on blind faith but instead see what logical conclusion you reach, if it’s different from the status quo, you might be onto something.