One of the most-quoted lines from 2008’s The Dark Knight is “you either die a hero or live long enough to see yourself become the villain.” Director Christopher Nolan has now responded to the fervor of this quote, saying he wants people to know he did not write it and didn’t originally understand what it meant.

Speaking to Deadline, Nolan said he feels “plagued” by that line, which was written by his brother, Jonathan Nolan. “It kills me, because it’s the line that most resonates. And at the time, I didn’t even understand it,” he said.

Looking back on it, Nolan now understands what his brother was trying to convey with that particular line, which was delivered by Harvey Dent (Aaron Eckhart).

“I read it in his draft, and I was like, ‘All right, I’ll keep it in there, but I don’t really know what it means. Is that really a thing?’ And then, over the years since that film’s come out, it just seems truer and truer,” he said. “In this story, it’s absolutely that. Build them up, tear them down. It’s the way we treat people.”

The Dark Knight was Nolan’s second Batman movie, following 2005’s Batman Begins. Christian Bale portrayed Batman in those films and the third, The Dark Knight Rises. The Dark Knight featured a memorable performance by Heath Ledger as Joker in one of his final performances. Ledger won a posthumous Academy Award for playing the villain.

As for Nolan, his latest movie is Oppenheimer, which is up for 13 Academy Awards, including Best Picture and Best Director.