The local bar was so sure that its bartender was the strongest man around that they offered a standing $1000 bet.  The bartender would squeeze a lemon until all the juice  ran into a glass, and hand the lemon to a patron.  Anyone who could squeeze one more drop of juice out would win the money.

Many people had tried over time (weight lifters, longshoremen, etc.) but nobody could do it.

One day a scrawny little man came in, wearing thick glasses and a polyester suit, and said in a tiny, squeaky voice,  "I'd like to try the bet."

After the laughter had died down, the bartender said OK, grabbed a lemon, and squeezed away. He then handed the wrinkled remains of the rind to the little man.

But the crowd's laughter turned to total silence as the man clenched his fist around the lemon and six drops fell into the glass.

As the crowd cheered, the bartender paid the $1000, and asked the little  man, "What do you do for a living? Are you a lumberjack, a weight lifter, or what?"

The man replied, "I work for the IRS."