Answer: Nothing, there isn't one
As Mark Twain observed, a German joke is no laughing matter.
Sadly for the nation that brought us everything from Beethoven to lederhosen, it seems that everyone agrees.
Germany has been voted the least funny country in the world in an international poll.
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But before you permit yourself a dry British chuckle at the news, we came fourth from bottom – apparently, we’re simply not as funny as we think we are.
The survey of 30,000 people in 15 countries was conducted for social networking site Badoo.com, whose spokesman Lloyd Price said: ‘Germans are brilliant at so many things, including making cars and beating us at football.
'Unfortunately, telling jokes isn’t always one of them. If only there was a comedy World Cup, we might stand a chance against them.’
The stereotype of German humourlessness is believed to derive from their reputation for efficiency, punctuality and rationality, presumed to be at the expense of humour.
Examples of German jokes include: ‘Yesterday, I met my friend Horst at the hospital. He’d swallowed a sponge. He says it doesn’t hurt but he’s always thirsty.’
If that left your ribs untickled, try this: ‘Plants grow very well if you speak kindly to them. Which is why I sometimes go into the garden and insult the weeds.’
Of Britain’s place near the bottom of the list, Mr Price said: ‘If we’re no good at football and no good at comedy either, it’s a bit of a pie in the face for us.’