About 25 years ago I had a very unusual experience which I've never been able to explain. I was in a restaurant with my Mum one day, she was chatting, I was listening. Suddenly I see a wave come from her head going across the room, it was a sine wave. Interesting hallucination I thought to myself. I followed it across the room for about 30 feet when it reached where people were queueing up to pay for their food. As it reached the guy at the head of the queue, who had just paid, it disappeared and as it disappeared he dropped his whole tray of food on the floor, he stood there in complete shock and obviously didn't have a clue why it had happened. I have never experienced anything even remotely similar since then. Now of course it could have been a completely random event with no connection to the wave I had seen. But if it wasn't is there any likely explanation for what happened?