Two sea monsters were swimming around in the ocean, looking for
something to do. They came up underneath a ship that was hauling
potatoes. Bob, the first sea monster, swam underneath the ship, 
tipped it over and ate everything on the ship.

A little while later, they came up to another ship, again hauling
potatoes. Bob again capsizes the ship and eats everything onboard.

The third ship they found was also hauling potatoes and Bob once 
again capsized it and ate everything.

Finally his buddy Bill asked him, "Why do you keep tipping over those
ships full of potatoes and eating everything on board?"

Bob replied, "I wish I hadn't, but I just can't help myself once I
start..... Everyone knows you can't eat just one potato ship."