If you lived within 200 miles of an American mall in 2008, you’ve heard this song. Maybe you’ve even danced to it in a drunken stupor. So what is it about Katy Perry’s lyrics that captures the feeling of a tumultuous relationship in a way that makes you wanna belt out the chorus with her?

The sentence structure is simple. It’s literally just a list of opposites: hot and cold, yes and no, in and out, up and down. This repetition makes the lyrics rhythmic, and borderline hypnotic — and that’s why they’re so catchy.

Simple words are best when you want to write something this memorable. Just imagine if Katy Perry had written: “You’re sizzling hot then you’re frigid. You agree then you say no. You’re down for whatever, but also cancel plans a lot.” Clunky and forgettable, isn’t it?

The actual lyrics get stuck in our heads because of the rhythm. Every word has one syllable and every sentence has five words. This consistency, paired with the swerving lyrics, mirrors the dramatic swings of a turbulent relationship.

By contrasting one extreme with the other, over and over again, Katy Perry puts the emotional rollercoaster of a volatile relationship into a form of catharsis that everybody can feel. Her lyrics don’t just describe instability. They show it through repetition.