This past week I had the same thing happen. I was not at a water fall. Again I ignored that urge. I was tired and asleep but aware. I was at the edge of a river and watching the water flow past me and again...it was the best thing to watch that water flow. Luckily I caught myself. I jumped and made the mad dash to the bathroom.
Our bodies do talk to us even when we are sleeping. Listen. Listen well.