The Jewish have GUILT down to a science!!  Courtesty of Hollis:

My mother once gave me two sweaters for Hanukkah. The next time we visited, I
made sure to wear one.  As we entered her home, instead of the expected smile, 
she said, "What's the matter? You didn't like the other one?"

A man called his mother in Florida. He said to his mother, "How are you doing?"
She said, "not too good.  I've been very weak."  The son then asked, "Why are 
you so weak?" She said,  "Because I haven't eaten in 38 days.  "The son then 
asked, "How come you haven't eaten in 38 days?"  She said, "Because I didn't 
want my mouth to be filled with food when you called."