One morning there was a young man bought some products from me. Firstly he bought 2 meters of 19mm diameter hosing and paid £3.50. After that he asked me some ideas about fish.

"I want to buy fish, but I didn’t know which are the best one to choose." He said.

"What’s your pond size?" I asked.

"It's quite big, maybe two square meters." He told me.

"The best choose is KOI（锦鲤） , because KOI are easy to keep, cheap and grow quickly." I said to him, he nodded in agreement.

For a long time I work with the fish ponds and met many customers, I knew some customers with fish keeping experience, some were poor or without any fish knowledge. If the customer is quietly looking at the same pond's fish for a little longer, bent or hand against the pond edge to have a detailed look, the meaning is they are with some fish keeping experience. If the customer looked at the fish and loudly talks, pointing at this one and that one randomly, the meaning is they are without fish keeping experience or poor. I have seen the young man hadn’t looked at any fish for a little long while of the time. So I thought he was a poor one.

"Did you have any fish keeping experience?" I asked.

"No!" He answered frankly.

"So, you can buy a small one, maybe about 4—6 inches should be better, after you got some experiences you can change to big ones." I said to him candidly.

He nodded and said: "I want to buy some fish that could clean the fish pond, because the fish pond will get dirty easily."

"I am afraid, actually no any fish can clean the pond, even including the sucker fish and pond snails." I told him authoritatively（权威地） .

"Why?" He didn’t believe me.

"Because, because the fish are too lazy! Maybe you could buy some such as Indian blue garra（墨头鱼） 4 for 10 quit, they’ll 24 hours on duty and will little bit help you." I didn’t know the proper answer.

"No, it is not the fish lazy, I am Mr. lazy." He said.

"No, you are not lazy, but fish." I said.