A man was in a shop which was selling gold fish and looking around when a family came to the counter and brought a gold fish and the shop keeper added the price up in seconds. After they had left, he asked the shop keeper how he was so add add the prices up in his head. The shop keeper told him that he only eats fish heads, so the man asked where can i buy only fish heads. The shop keeper tells him he can buy three for £5.00 from him. The man buys six of them and goes home. A week later he comes back and says I don't feel any different. The shop keeps says that he might need some more, so the man buys another six and goes home. He comes back a week later and says I still don't feel any different. Then he says "The shop down the road is selling fish heads at four for £2.00!" Then the shop keeper says you see, your getting more clever by the minute.