The most interesting aspect of this video is that it shows how our expectations and our focus can affect our perception of the world. When we are focused on the ball players in white, that focus screens out other stimuli such that we don't even perceive what is right in front of us. This phenomenon is known as inattentional blindness.When I watched the video I did see the guy in the gorilla suit (because I was familiar with the experiment and knew what to expect), but I missed the black player leaving and the color change of the backdrop. I missed those two because I was counting the passes and looking for the guy in the gorilla suit. Had I been focused on some other aspect of the video I might have missed other things as well.
Inattentional blindness is a common phenomenon that can occur in many different circumstances. Magicians, for example, often exploit this phenomenon when performing illusions. They will focus the audience's attention on one thing while actually performing the trick off to the side. Due to inattentional blindness, most people will miss the actual trick because they are focused somewhere else and thus the illusion appears to be the result of magic. Magicians call this misdirection and it can be accomplished by something as simple as where the magician is looking (humans have a tendency to follow the gaze of others, so if the magician is focusing his eyes on one area of the stage, the eyes of the audience will naturally be drawn there).
This phenomenon of inattentional blindness also explains why it is a bad idea to text while driving. When our attention is focused on a phone, there is a high likelihood that we will miss other important things that are going on right in front of us (like a pedestrian crossing the street).
More generally, when we see someone perform some amazing feat or do something that appears impossible, we should not immediately jump to the conclusion that this person has supernatural powers. Instead, we must seriously consider the possibility that we missed something because we were so focused on observing what was going on. Furthermore, even if we were playing very close attention to what was going on, we have to seriously consider the possibility that we missed something else because our attention was so focused on one area. Perhaps the real trick was going on behind our backs or off to the side and we missed it because our attention was focused elsewhere.
h/t to Richard Wiseman