Two little old ladies, Gertrude and Zelda, were sitting on a park bench near Golders Green having a serious conversation.

"Gertrude," said Zelda, "I don't understand something. I simply have no appetite lately.  No matter how much I try to eat, I have no appetite."

Gertrude said, "Listen Zelda, my doctor, the lovely Doctor Myers, once told me that if I didn't have an appetite I should take a little piece of herring before meals and I would soon get an appetite. So I tried it and it was true.  So take my advice, Zelda and try a little piece of herring before lunch and you'll see, you'll develop an appetite."

A few days later the two meet again in the park.

"Nu, Zelda, how do you feel now?  Did the herring give you an appetite?"

Zelda sighed, "I took your advice.  First I had a little piece of herring. Then I had a whole herring.  I really wanted to give it a chance, so I ate six herrings.  But Gertrude, your advice didn't work for me.  Would you believe, when lunch time came, I had absolutely no appetite!"