Ole and Sven went fishing one summer and decided to rent a boat from the resort instead of fishing from the shore. They rowed out a ways and started to fish, catching one fish after the other.
Ole says to Sven, "I wish we could mark this spot. It’s the best fishing I've seen since I was a boy."
Sven replied, "I got some chalk in my tackle box, so why don't I put an X right here on the bottom of the boat?"
Ole laughed, "But Sven, what if we don't rent the same boat next time?"