William Sangster, preaching giant of a previous generation, used to tell the story of "The Spectre on the Brocken." The Brocken is the highest peak of the Harz Mountains in Germany. Many people lived in fear of it because it was said that a giant resided there. He had been seen many times by credible witnesses.
Eventually, skeptics decided to settle once and for all the story of the Spectre. They discovered the witnesses actually had seen something. It had been noted that the giant was only seen at sunset or sunrise. They also noticed he only appeared on bright days. What did the witnesses see? Researchers discovered the spectre was the shadow of their own bodies. It was a reflection, and people actually were frightened of their own shadows.