Could you miss a gorilla walking right past you?
Gorillas in our midst: Sustained inattentional blindness for dynamic events
People counting basketball passes in a video often completely missed a person in a gorilla suit walking through the middle.
Ig Nobel 2004
Viewers watched a short video of two teams passing basketballs and were asked to count the passes made by one team. Partway through, a person in a full gorilla costume strolled into the scene, thumped their chest and walked off.
About half of the viewers never noticed the gorilla at all. When we focus hard on one thing, our brains can quietly ignore something huge and hairy right in front of us.
Count the passes, miss the gorilla. Classic.