“Insanity is doing the same thing, over and over again, but expecting different results.”

“Unfortunately, Susan didn't remember what Jane Fulton once said, 'Insanity is doing the same thing, over and over again, but expecting different results.”

“One of the better definitions of insanity - doing the exact same thing over and over and expecting the result to be different.”

“Do you know what Albert Einstein's definition of insanity was?" "No." "Doing the same thing over and over and expecting different results.”

“My dad used to say the definition of stupidity was doing the same thing over and over again and expecting a different result. Or maybe that was the definition of crazy.”

“Einstein wrote that insanity is doing the same thing over and over and expecting a different result. That said, is it crazier to repeatedly throw yourself against a window, or to repeatedly open that window, believing the creatures that are throwing themselves against it might come into your house, take a look around, and leave with no hard feelings?”