He who knows nothing is closer to the truth than he whose mind is filled with falsehoods and errors.

An empty position is easier to correct than a wrong one. Someone who knows nothing can simply be told; someone confidently mistaken has to give something up first, and giving up a belief costs far more than acquiring one. That is why expertise in a neighbouring field can be worse than ignorance when the details differ.

Where are you operating on information you picked up years ago and never rechecked. Old certainties about money, health, a person, an industry are the likely candidates, because nothing has forced a review. To admit you no longer know is not a step backwards; it is the position from which learning becomes possible again.