evidence: The quote "The definition of insanity is doing the same thing over and over again and expecting different results" is popular, being widely attributed to Einstein (probably incorrectly). Unfortunately it's often used to support a common and dangerous fallacy: that if you're trying something and it's not working, you must not be using the best strategy and you must try something else. It's easy to see the fallacy using a thought experiment. Imagine you must regularly play a lottery which offers red tickets and black tickets, and red tickets have twice the probability of winning compared to black tickets. So you choose red tickets, but you don't win. Would Einstein tell you to start choosing black tickets instead? Hopefully not! [...] Of course, one must also avoid stubbornly sticking to a strategy which is not the best available.