Hypnosis

The man was so convinced that hypnosis was not real, he created his own story about how these folks were getting up and leaving and then coming back. The brain gave a reason to dismiss the whole thing. In order for him to maintain his belief system, he had to sort of give a gift of belief that this can't possibly be happening, so it must be something else. If you're forced to see an aberration, it's shattering. It really knocks the earth off under your feet.