Consider first a statement that everyone agrees with. For example,
Everyone said that was a great party.
Now invert the order:
"That was a great party," said everyone who attended.
Note that this is the same pattern as your sentence except everyone is saying it instead of nobody.
We can keep the sentiment the same but state it as kind of contrapositive like this:
No one ever said that that was a dull party.
Now invert the order:
"That was a dull party", said no one ever.
It helps to add the appropriate pauses and emphasis too. So, pause for dramatic effect after the word party, to get people thinking that you're done speaking and have just uttered a completely absurd statement, then follow up with
"said no one ever."
Which turns your statement on its head and lets the listeners know you're not crazy after all- just making a small joke. It also helps to place a little extra emphasis on the word ever.