Leo Rosten, the great Jewish writer and authority on Jewish humor, listed as one of the characteristics of Jewish humor revenge over the oppressor by the use of guile or circumstance. This is such a story:   Moshe was sitting at the bar staring at his drink when a large, trouble-making biker steps up next to him, grabs his drink and gulps it down in one swig and menacingly says, "Thanks Jew Boy, whatcha going to do about it?"   Moshe burst into tears.   "Come on, man," the biker says, "I didn't think you'd CRY. I can’t stand to see a man crying. What’s your problem?"   "This is the worst day of my life," Moshe says. "I'm a complete failure. I was late to a meeting and my boss fired me. When I went to the parking lot, I found my car had been stolen and I don't have any insurance. I left my wallet in the cab I took home. I found my wife in bed with the postman and then my dog bit me.   So I came to this bar to work up the courage to put an end to it all. I buy a drink; drop a capsule in and sit here watching the poison dissolve; then you show up and drink the whole thing!   But enough about me, how's your day going?"