pay attention, look around

When I was around 10 years old, my family went on a vacation up to Maine. During this trip, we found a walking path with a footbridge to a little island. Along this path was a place where the path passed a bunch of mud on one side. Past the mud, perhaps a hundred feet or so out from the path, was water. It was low tide. My Dad and I stood on this path, facing the water and he said, "I bet I throw this rock to the water."

I looked at him and at the water off in the distance and said, "No way. I bet you can't."

We went back and forth for a little while and I extracted more conditions, such as he couldn't leave the path and he had to use his own arm and no tools to throw. I don't remember exactly what we bet, but it was probably something along the lines of "If I win, you say 'You were right, Father.'".

Finally, after we agreed, he turned around and threw the rock the 10 feet into the water on the other side. On the OTHER side of the path, there was only a few feet of rocks and then water.