Fictional attribution in the movie The Emperor's Club (2002), given by Kevin Kline (as William Hundert); also attributed to Diogenes, without sources; no published occurrences of this statement prior to the movie have been located in any of the Aristophanes Plays or Fragments.
Misattributed
Source: IMDb, "Memorable quotes for The Emperor's Club" http://www.imdb.com/title/tt0283530/quotes, Internet Movie Database, www.imdb.com
Source: Two pages attributing it to Diogenes: http://www.prohibitionists.org/Background/Party_Platform/quickquotes/QQ-education.htm http://www.ryanbalton.com/funstuff/forb_seniorquotes.htm