This was a brief ride; via random Instagram, I stumbled onto this tweextaposition:

…and I thought, vaguely, “is Pam’s quote really a Nietzsche quote? It doesn’t quite sound portentous enough…”

So I googled around, found an indefinite number of “Nietzsche” motivational graphics bearing the quote, and found this whipsaw blogpost which goes to great lengths to track the source of the quote … and finds elderly US Senator Robert Byrd at the centre of it all:

Still not satisfied, we turned to where we should have started, Google Book Search. This time, the quote yielded only two hits. Neither of them were works by Nietzsche. The …books were: Letter to a New President: Commonsense Lessons for Our Next Leader, by Robert C. Byrd and Steve Kettman, published in June 2008, and [other…]

The latter book is one of a seemingly infinite attempts to write a corporate “best practices” bible, while the former is, of course, co-authored by the longest-serving Senator, 91-year-old Democrat Robert C. Byrd of West Virginia, who was first elected to Congress in 1952. Our verdict: Byrd’s coauthor came across the leadership book and cribbed the quote, which he and Byrd used as a slam against Presitard Bush, writing on page 87:

Friedrich Nietszche presciently identified the manner in which much of the public would react to President George W. Bush’s fast and loose way with the truth when he commented, “I’m not upset that you lied to me, I’m upset that from now on I can’t believe you.”

So there you have it: our source. Tumblr and the Internet were punk’d by the oldest member of the U.S Senate. As we used to say in the ‘70s, have a nice day!

https://peterfeld.tumblr.com/post/70200626/im-not-upset-that-you-misquoted-nietzsche-im

However: the blogpost then spins on a dime and concludes:

Commenter below points out: it is actually a derivation of a quote from Neitzsche’s Beyond Good and Evil.

Aphorism number 183
“Not that you lied to me but that I no longer believe you has shaken me.”

http://nietzsche.holtof.com/reader/friedrich-nietzsche/beyond-good-and-evil/aphorism-183-quote_11a7a96dd.html

So there you have it: mirabile dictu, it is actually legit. Paint me surprised, and I’m going back to my coffee.