Quotes Uncovered: The Universe and Stupidity

Seventeen weeks ago I invited readers to submit quotations for which they wanted me to try to trace the origins, using The Yale Book of Quotations and more recent research by me. Hundreds of people have responded via comments or e-mails. I am responding as best I can, a few per week.
Maria asked:

“It is amazing what you can accomplish if you don’t care who gets the credit.” Reagan? Truman? Lincoln? Some 19th-century white woman I saw credited with it on a poster many years ago?
Please help.

The Yale Book of Quotations, which attempts to trace all famous quotations to their earliest documented occurrences, cites:

“There is no limit to what a man can do so long as he does not care a straw who gets the credit for it.”
Charles Edward Montague, Disenchantment (1922).

Bette Neumann asked:

“The most powerful force in the universe is compound interest,” or “Compound interest is the greatest mathematical discovery of all time.”
It’s often attributed to Albert Einstein, but debunked by Snopes.

The YBQ cites The New York Times, May 27, 1983:

Asked once what the greatest invention of all times was, Albert Einstein is said to have replied, “compound interest.”

Snopes is of course correct that the Einstein attribution is undoubtedly apocryphal.
Antoine asked:

“Two things are infinite: universe and human stupidity. But I’m not sure for the universe.” (Or something approaching this. I’ve always heard it in French; the translation is mine.)
It is usually assigned to Einstein, what can you say about it?

The Yale Book of Quotations quotes as the earliest evidence found for this:

“Only two things are infinite, the universe and human stupidity, and I’m not sure about the former.”
Attributed to Albert Einstein in Robert Byrne, … 637 Best Things Anybody Ever Said (1990).

Again, the attribution to Einstein is undoubtedly apocryphal.
Do any readers have any other quotations whose origins they would like me to attempt to trace?