I remember back in College Composition 1 (a basic college writing course that I took... five years ago? Six years ago? Wow, but I'm getting old...) my professor took the sentence "Rex died with his boots on" and inserted the word "just" in various configurations.
Just Rex died with his boots on.
Rex just died with his boots on.
Rex died with just his boots on.
Today, ESPN the Magazine's Jorge Arangure Jr. took the word "not" and, albeit unintentionally, provided a similar illustration.
"Rarely does a Yankees regular-season game, at least not one against the Boston Red Sox, elicit such attention," Arangure writes - a statement which would lead most readers to assume that Yankes vs. Red Sox is a rivalry roughly on the scale of, (to use an analogy from the NHL), Coyotes vs. Lightning.
Nice work, dude. By misplacing one word, you've managed to not only completely change the meaning of your sentence, but also insult one of the biggest rivalries in American sports.