Since I laughed out loud at this, perhaps I should explain the joke, since it's obvious that no one "got it."

You see, the original quote was "As a famous man once said: "Trust, but verify"."

Now, if you heed this advice in full, you can only trust that the famous man actually said "Trust, but verify" if you verify it first. A citation is simply a way to verify that a famous man actually said it.