Lorde talked about what inspired this song at a concert:
I wrote this song on a Monday in February, last year. And I wrote it following this weekend where my and my sister and our best friend threw this huge house party at my place. Like the kind of house party where people eating all the shit out of your fridge and freezer, like, defrosting things in your microwave… And at the end, everyone just crashed at my house, on the floor of every room. And there was one guy who
came around after lights out… and he crashed with me and my best friend in my bed. And I couldn’t sleep. And he’s like ‘What is it?’ and I was like ‘What we just did is cool. It’s cool. You know, doing this thing, throwing this house party, it’s adult. And there’s something scary about doing something that is in a different world than the one you know. My whole life I’ve been doing the things that kids do, you know, fucking around and not having any responsibility. It’s scared me to think of
having one foot in that adult world because who says that we can go back? Like, can you be a kid and still do adult things? Do you have to leave that world behind? And this is the thought that keeps me up at night, all the time.
