The Auckland teenager, who was spotted singing at school when she was just 12, said her songwriting rejected that. "If I write songs about anything else then I'm not writing anything that's real."
Lorde's song went to No1 in New Zealand after its March release. It has gone on to crack American audiences, topping Spotify's "Most Viral" chart. She is working with music producer Joel Little on her album, due for release in September.
She told New York music magazine The Cut that the album would "paint this picture of who I am as an artist" and include some intimate songs about relationships.
But she quickly said that did not mean ex-boyfriends.
"I try to stay away from talking about boys all the time. You can go to Taylor Swift to hear that."
Lorde told the magazine that life had changed since her EP came out.
"I get recognised, which is weird, when I'm at a restaurant and I've got my mouth full of food. I had to make a different Facebook the other day because I get weird messages from dudes saying, 'We're going to be the best of friends', and I'm like, 'Ewww, we aren't'." But for the most part, people are really kind."
But she said her large family helped keep her feet on the ground.