A traveling salesman visits a small town in the Midwest and sees a circus
banner reading, "Don't Miss the Amazing Goldstein!"

Curious, he buys a ticket and sits through the usual circus acts: animals
clowns, contortionists, etc. Suddenly, trumpets blare and all eyes turn to
the center ring. There in the middle of the ring is a table with three
walnuts on it.

In comes a little old Jewish man, five feet tall and barely able to walk 
to the table. He unzips his pants, whips out his long shlong, and proceeds 
to smash all three walnuts with three mighty swings! The crowd erupts in
thunderous applause as the elderly Goldstein is carried off on the shoulders
of the clowns.

Ten years later the salesman visits the same little town and he sees a
faded sign for the same circus and the same "Don't Miss the
AmazingGoldstein." He can't believe the old guy is still alive much less
still doing his act! So he buys a ticket and sits through the various acts.

Finally, the center ring is illuminated. This time, instead of walnuts,
three coconuts are on the table. As before, old Goldstein takes forever to
make it to the table. He unzips his fly and proceeds to smash the coconuts
with three swings of his amazing shlong. The crowd goes wild!

The salesman requests a meeting with him after the show. In Goldstein's
dressing room, the salesman tells him he's never seen anything like his act.
But he wants to know why he's now smashing coconuts instead of the much
easier walnuts.

"Vell," says Goldstein, "My eyes aren't what they used to be!"