...screamed my family in incredulity, and in unison, at a restaurant as they wondered how they could have missed something so obvious in the video that I just shared with them. I was there, grinning, waiting for the same reaction that I had when I saw this video . Before you read further, I encourage you to watch it and come back here.
Did you pass the test? If yes, the rest of the post does not apply to you. You may leave now :-).
Just kidding! The reason we did not see the gorilla the first time around is that we are focused on a difficult cognitive task that requires our full attention to succeed. That focus means that we cannot see the other things that also need our attention - in this case - an adult gorilla walking around thumping its chest in plain sight!
This cognitive limitation is called selective attention or inattentional blindness. Ever since I came upon this phenomenon, I have been fascinated by its manifestation in everyday life. The scientists who created that video: Christopher Chabris and Daniel Simons, went on to publish a fascinating book called "The Invisible Gorilla" where they explain this curious failing of the human mind, tell intriguing stories about its effect in daily life, and advise us on how to minimize its detrimental effect.
This book humbled me, making me less sure of myself. There is usually a monkey in my brain these days, asking me: "Are you sure?". It has helped me temper my confidence. It has helped me detect and fill gaps in my theories. It has motivated me to address a problem from different angles. And, more importantly, it has helped me seek different perspectives - even contrarian to my own point of view, just so I don't miss a gorilla hiding in plain sight.
Check out the book. I think it will make you a more self-aware person. If you read all the way through here, you may want to read this blog post about Upstream Thinking that also talks about inattentional blindness.