This was heard on the Prairie Home Companion radio program's annual joke show
(a rebroadcast from last year.
A Jewish man was to be knighted. He knelt before the queen and was to recite
some words in Latin. Since he didn't know Latin and forgot what he was to
say, he recited a line in Hebrew from the Passover seder. The queen turned
to her attendant and said, "Why is this knight different from every other
night?"