A Jew was traveling on a train, peaceably reading his newspaper, when a Gentile who had noticed his yarmulke came along and sat down across from him. The Gentile was a brusque and nosy sort, and abruptly he remarked, "I'm very intrigued. You Jews are always so successful wherever you go. Even when you're oppressed and persecuted, you manage to come back and thrive. So what's your big secret?"
The Jew lowered his newspaper. "It's pretty basic," he said. "We work hard, we study hard. We stick together. It's as simple as that."
But the Gentile would not accept this as an answer. "No," he said, "there's got to be some secret. So come on, tell me." And back and forth they went like this for a while: with the Jew giving rather ordinary explanations, and the Gentile pressing him for some secret gnosis. Finally the Jew relented: "all right. Fine. You got me. Look, the thing of it is, it's the herring."
"What?" asked the Gentile, incredulous. "What herring? What are you talking about?"
"Well," explained the Jew, "we eat a very special kind of herring. It increases a person's smarts. Gives a massive boost to the intellect. Without the herring, we'd be nothing."
"Where I can get this kind of herring?" his interlocutor asked.
"Oh, you won't be able to get it anywhere. Don't even bother. No Jew is likely to give out the secret herring to a non-member of the tribe." At this, he took out his paper bag lunch—and from it, a herring sandwich wrapped in wax paper. "In fact, I have to eat mine now. I have an important business meeting this afternoon."
"Wait," urged the Gentile. "I've got to have that."
"What did I just tell you? I have a meeting. Now if you don't mind, let's be done."
"No. I'm serious. I'll give you twenty bucks for it."
The Jew laughed at this proposal. "Twenty bucks. Yeah, right."
"Forty, then," the Gentile said, but the Jew waved him off. "Sixty," the Gentile continued, and on went the bargaining, until the desperate Gentile had gotten himself up to two hundred dollars for the sandwich.
"All right," relented the Jew. "For two hundred dollars, I guess I can part with it." The Gentile emptied his wallet and the Jew handed over the sandwich, which the Gentile swiftly unwrapped and tore into greedily.
But "hey," remarked the Gentile, his mouth full, his eyes suspicious: "this tastes just like regular herring."
"See?" said the Jew. "It's working already!"