Good one, TIS.
That kind of reminded me of one.
Two older priests and a young priest go for a day of fishing on the lake. They get in the boat and are in the middle of the lake when the oldest of the three says, "I forgot my bait in the car." He promptly steps out of the boat, walks across the surface of the lake, gets his bait, and walks back to the boat across the lake's surface.
A moment later, the other older priest announces that he left the sandwiches in the car. He also walks across the surface of the lake and back in order to get the sandwiches.
The young priest then stands up and says he had beer in the car that he was going to get. He steps out of the boat and plunges deep into the lake.
The first priest turned to the second and says, "Gee. We should have told him where the stones are."