A man walks into a bar and screams at the top of his voice, "I know the funniest joke ever! £10 and I will tell you it!" A man at the far end, a regular holds up a £10 pound note and the man comes over and whispers the joke in his ear. The bar regular falls off his stool and laughs uncontrollably for around 30 minutes and as a result, is taken to the hospital.
A second man is curious at how funny this joke could be so he holds up a £10 note and the man whispers the joke in his ear. The man howls with laughter with tears streaming down his face and continues to laugh for 60 minutes. Eventually he is taken to hospital.
Old Gus at the corner of the bar is intrigued. No one has seen Old Gus laugh for over 30 years. No joke has ever been able to make him laugh, but he decides to throw £10 down anyway, just to hear it. The man comes over and whispers the joke to Old Gus. Old Gus then proceeds to slam the table whilst chortling like a hyena for 90 minutes. He is then eventually taken to hospital.
There is one man left at the bar, the bartender and the guy goes up to him and says, "Want to hear my joke, it's the funniest joke ever made and I will tell you it for just £10, then I'm off." And the man responds, "No, because then there will be no one left to call in the ambulance!"