Politicians are like nappies, they should be changed regularly and for the same reason.

This quote has been credited to multiple sources, including Mark Twain, José Maria de Eça de Queiroz (translated from Portuguese), and "unknown, originated around 1992" (see The Quote Investigator entry "Politicians Are Like Diapers. They Should Be Changed Regularly" and The Big Apple, Entry from December 12, 2009: “Politicians and diapers should both be changed regularly, and for the same reason”). It may have originated in a Reader's Digest joke column. A columnist for the Indiana Gazette quotes a version of this (February 17, 1987) that he says he got from someone who got it from a "Reader's Digest fan."