A Welshman is walking on the beach when he finds a brass oil lamp and a genie pops out and offers him three wishes.
The Welshman says: “I’ve no doubt what my first wish is, genie. Give me a bottle of Brain’s SA that never runs out!”
The genie hands him a bottle and the Welshman takes a long swig but it’s still full. He pours some into his hands and laps it up - and the bottle is still full. No matter how much he pours, the bottle never runs out.
“Master, you still have two more wishes,” says the genie.
“I know what I want,” says the Welshman. “Give me two more just like this.”