Wise words but who said them?

Most people know the quote, and most people attribute it to Einstein when asked.

So it comes as quite a surprise for them to hear it wasn't him who originally said it.

Even weirder, it turns out the attribution is all a big mistake. An editor used the wrong version in Montana's Bozeman Daily Chronicle, and as a resut found it was said by a character in a mystery book titled "Sudden Death".

Narcotics anonymous

There's an early reference to the quote in a 1981 pamphlet produced by Narcotics Anonymous - and organisation run along similar lines to Alcoholics Anonymous:

Not all the women are willing to admit they needed to be “restored to sanity.” In fact, one of them adamantly maintains that she had never reached a point of insanity. But another remarks, “Insanity is doing the same thing over and over again and expecting different results.”

There's a detailed history of the quote over at quoteinvestgator.com.

The truth of the quote itself is totally correct at a logical level, which is assuming all possible variables remain the same. The problem is, in real life most don't, otherwise the counter saying "If at first you don't succeed, try and try again"  would not serve any purpose. For example, an athlete trying to beat his highest high jump score is actually refining his technique and becoming fitter with each attempt, so by the time he does actually make it he is not the same person he was at the first time. However, a scientific experiment where each individual part is perfectly adjusted to be the same each run, will always produce the same results. Well, unless you take things down to the quantum level where Heisenberg or the many-worlds interpretation makes an appearance - or perhaps we've just come full circle back to the Mandela Effect?