(…) It’s about being out of a relationship that really isn’t good for you but you can’t help but wanting it back anyways or wanting the person back (…) just a friend that just fucked you up or loved one in any way it’s just that relationship that’s kind of a bit self-destructive I would say maybe that you just can’t help but love (…).

— Zara Larsson: The Meaning of “Ruin My Life”

I released this as a single [in 2018] thinking my album would be coming soon, so it still feels like part of the album. Sometimes people act like I deleted those songs, but they’re still out there.

— via Apple Music

In an interview with Popjustice, Zara was asked about the song’s feel, where the reporter said that the song was “emotional but not in a straightforward ‘hi-I’m-a-love-song-way’” and further that there was a “darkness” to the song.

Absolutely, I can’t lie: I’ve been there, when you’re coming out of a bad relationship and you just know this person is really bad for you, but you can’t help wanting to go back. You’re like: “I know he’ll ruin my life, he’ll break my heart and I won’t be able to eat or sleep for three months, but I WANT IT NOW”. I think everyone’s been there. Or after two drinks you can’t stop yourself sending the texts. But… I also argue against myself when it comes to songs. I’m very careful with things I say. And I don’t want people —young girls and women— to listen to the song and… Like, I don’t want to be a girl who promotes bad relationships. “Just go back to him, it’ll be fine”. I don’t want to do that. But I do also want to be an artist who can express something I’m feeling or that I’ve been through.

A clean version, replacing “fuck” with “ruin” exists.