Did you know of the Invisible Gorilla experiment?

In this psychological assessment, subjects believed they were supposed to count passes between players on a basketball team. In actuality, they were being evaluated on something else entirely. What most subjects did not notice while tallying the tosses of the ball was that a man in a gorilla suit had walked into the court. Focusing so strongly on 1 component blinded the subjects to the big picture.

If you want to know more, read the book “The Invisible Gorilla”, or check on wikipedia:
https://en.wikipedia.org/wiki/Inattentional_blindness#Invisible_Gorilla_Test