An Irishman, an Englishman, and a Scotsman are out walking when they capture a leprechaun. It agrees to give each of them one wish.
The Scot says, “My grandfather was a fisherman, my father’s a fisherman, I’m a fisherman, and my son will be a fisherman. I want the oceans full of fish for all eternity.” The leprechaun winks and instantly the oceans are teeming with fish.
Amazed, the Englishman says, “All right. I want a wall around England, protecting her, so that no one will get in for all eternity.”
Again the leprechaun winks, and suddenly there’s a huge wall around England.
The Irishman says, “I’m curious — please tell me more about this wall.”
“Well,” says the leprechaun, “it’s 150 feet high and 50 feet thick, protecting England so that nothing can get in or out.”
The Irishman says, “Fill it up with water.”