"Squeezing Juice out of a Lemon" joke

A local bar was so sure that its bartender was the strongest man around that
they offered a standing $1,000 bet. The bartender would squeeze a lemon until
all the juice ran into a glass, and then give the lemon to a patron. Anyone who
could squeeze another drop of juice out would win the money. Many people tried
but nobody was able to do it.
One day a scrawny, little man came in, wearing thick glasses and a polyester
suit. He said in a squeaky voice, "I'd like to try the bet." After the laughter
died down, the bartender grabbed a lemon and squeezed it. Then he handed the
wrinkled remains of the rind to the little man who clenched it in his small
fist.
Soon the crowd's laughter turned to total silence as six drops of juice fell
into the glass. As the crowd cheered, the bartender paid the $1,000 and asked
the little man, "What do you do for a living?"
The little man replied with a winning smile, "I work for the IRS!"