If you say it over and over and over and over again, it becomes quite catchy. Maybe if someone makes a rude gesture at you while you're out driving around, you can say it to yourself and you'll feel better. Or maybe if you want to freak someone out that's bugging you and won't go away, you could say it to them too. I'm sure the magic would work wonderfully and they'd leave you alone. If, in ignorance, that nuisance of a person asks what you just said, you can tell them it was a jinx. They won't know the difference and I'm sure after hearing such news they'd definitely leave you alone. How magical. Thank you Mary Poppins.