Quotes can be useful in your content, either as a lead-in for your material or as an example of how you used their message to solve a particularly sticky situation in your business. (Of course, as long as they aren't tired clichés.)
The problem lies when a quote is either incorrectly worded or was never actually said by the identified person.
"The definition of insanity" is an example of the latter. Einstein did not say that sentence and there is nothing that alludes to his ever doing so.
Next, take the film Casablanca starring Humphrey Bogart. "Play it again, Sam" is one of the most misquoted lines in cinema, has been a basis for many impressionists' acts, and was even the title of a Woody Allen film about a neurotic film critic obsessed with — you guessed it — Casablanca.
It is important to always research and verify a quote before ever using it. That doesn't mean finding any old reference on the web that contains it. You need to use sources that specialize in verifying and documenting quotes.
Saying "that's close enough" or "people will know what I mean" doesn't cut it. Because when your customers realize the quote is wrong, they won't trust the rest of your materials to be correct either.
For those interested, here is the dialogue from Casablanca, and the two times when something close to the misquoted phrase is said.
The first occurs when Ilsa (Ingrid Bergman) asks the piano player Sam to play "As Time Goes By".
Ilsa: Play it once, Sam. For old times' sake.
Sam: I don't know what you mean, Miss Ilsa.
Ilsa: Play it, Sam. Play "As Time Goes By."
Later in the film, a distraught and drunk Rick asks Sam for the same song.
Rick: You know what I want to hear.
Sam: No, I don't.
Rick: You played it for her, you can play it for me!
Sam: Well, I don't think I can remember...
Rick: If she can stand it, I can! Play it!
Notice that the word "again" never occurs in either scene.
© 2019 Michael Marrer, Silver Lake Wordsmiths & Marrer Enterprises, Inc.