During my recent sourcing edits on this page, I removed this variant of "Fool me once shame on you, fool me twice shame on me" as I could find no indications of any published source for it: "If someone betrays you once, it’s their fault; if they betray you twice, it’s your fault." I did find a similarly unsourced variant ending with "if they betray you twice, it’s yours." I see no reason to believe either of them actually originated with Roosevelt. ~ Kalki 20:07, 11 October 2007 (UTC)
Possible origin for the disputed quote 
Great minds discuss ideas, average minds discuss events, small minds discuss people.
French writer/poet Louis Farigoule (1885-1972), better known as Jules Romains, is credited with saying, "Les esprits d’élite discutent des idées, les esprits moyens discutent des événements, les esprits médiocres discutent des personnes". Although I've not been able to find a source for this quote so far.