Michael Shermer is the founder/publisher of Skeptic Magazine, and author of several books, including 'Why People Believe Weird Things'.
The main part of the video explores the topic of perceptual blindness, with a demonstration for the crowd.
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This was pretty amazing for me. Watch the short video he shows at around 3:00 and follow the instructions and concentrate and count the passes. Then view the results. If you were like me you will be in for a big surprise!
PLEASE DON'T SPOIL THIS FOR ANYONE ELSE - Thanks