There was a Captain of a ship, and everyday at a certain time
he would lock himself up in his cabin and look inside a
mysterious black box.

He did this every day, but he told
nobody what was inside that box.

Then one day he died and in
his testament he wrote: "Now you can open the black box."

So they opened the black box.

And what they found was a
piece of paper, on it was written "Starboard is right, port is left."