This anecdote proves it. Hunter S. Thompson wrote a few days ago:

When young Bush was at Yale in the Sixties, he told the same joke over and over again for two years, according to some of his classmates. One of them still remembers it:

There was a young man named Green

Who invented a jack-off machine

On the twenty-third stroke

The damn thing broke

And churned his nuts into cream.


Thanks to Barlow for the link.