Things that weren't actually said, but became myths
Similarly, the statement "A billion here, a billion there...." is frequently attributed to Everett Dirksen. HOWEVER, this may be an urban legend created by a misquote of Dirksen by a newspaperman, as noted by the Dirksen Center: Update, May 25, 2004. A gentleman who called The Center with a reference question relayed that he sat by Dirksen on a flight once and asked him about the famous quote. Dirksen replied, "Oh, I never said that. A newspaper fella misquoted me once, and I thought it sounded so go that I never bothered to deny it."
See also Willie Sutton and "where the money is."