The video link I posted shows that when we are focusing on one thing, we are unaware of our other surroundings. Similar to the video of the people passing the basketball, and a gorilla walking by. I watch the show Brain Games on Netflix, and it is all memory, perception and optical illusions that illusionists test on people and I think it is very cool and interesting to watch. As a viewer, I thought that I would catch all of the illusions, but I didn't! "Not everything seen is what meets the eye"