|from the RNS article|
I thought of a few others. A quotation that begins "People are unreasonable, illogical, and self-centered. Love them anyway..." has been attributed to Mother Teresa, as well. (Riess discussed another "Mother Teresa" quotation that actually came from Richard Attenborough.) The "love them anyway" saying came from a writer named Kent Keith: see here and here.
A long time ago I read that the quotation, "You can fool some of the people all of the time..." was attributed to Lincoln---to a specific date and place, in fact---but actually dates from the later 19th century and was included in a 1901 book of Lincoln's witticisms. See here.
I've never seen the saying "God helps those who help themselves" in a meme, but I've known a few people who thought it came from the Bible. The saying has been attributed to Aesop, and also to Benjamin Franklin.
(It's actually quite contrary to the Bible, except in a kind of Horatio Alger hermeneutic, for although Proverbs extols hard work and virtue, the Bible does not primarily teach competency and self-reliance. Rather, a key biblical theme is that God helps people who cannot help themselves; he takes the side of the sinful, helpless, and incompetent (cf. 2 Cor. 12:10). Proverbs 28:26a actually says, “He who trusts in his own mind [himself] is a fool.”)
One other I can think of: the saying of John Wayne's, something to the effect that "Courage is being scared to death but getting in the saddle anyway." Apparently he never said that in any of his movies. It's a good thought, nevertheless. Most of these quotations are good thoughts, too, whether or not correctly attributed.
(After I first posted this, a former student alerted me to the popular meme attributed to C. S. Lewis, "You do not have a soul..." : http://mereorthodoxy.com/you-dont-have-a-soul-cs-lewis-never-said-it/ )