Much has been made of Jared Leto’s insistence on staying in character as The Joker while filming Suicide Squad. If you’ll remember, his co-star Will Smith says there was “not a single word exchanged off-camera” between the two of them. He sent Margot Robbie a dead rat. So yeah, Leto went all in. He’s not the only young actor though playing a major villain in a franchise film who got a little obsessive about his character. According to his fellow actors, Adam Driver stayed in character while filming Star Wars: The Force Awakens and would refuse to take his Kylo Ren mask off in between takes.

John Boyega told Rolling Stone it was “intense” to work alongside Driver who admitted he wanted to “forget [he was] in Star Wars” while filming. The magazine notes the Girls star was “was determined to take the role of Kylo Ren as seriously as anything he's done.”

Says Boyega of Driver’s dedication:

Do your thing, man. I mean, for me, I follow what Laurence Olivier or someone said: ‘Just act.’ But it was great to see him go for his process.

[For the record, it was Olivier who told Dustin Hoffman, who was attempting to stay awake for three straight days on the set of Marathon Man, “Dear boy, Why don’t you just try acting?”]

If you’re curious, [SPOILER ALERT] Driver eventually did have to take the mask off as the Rolling Stone article also confirms that during Kylo Ren’s climatic lightsaber duel with Finn, the mask is knocked from his face, revealing the real Kylo. [END SPOILERS]

It shouldn’t be said that one acting method is better or worse than the other or that Driver (or Leto) are eccentric goofballs for this dedication to their craft. But it is remarkable how different actors with different styles can all turn out great work. If Adam Driver leaving on his Kylo Ren mask and skulking around set ignoring his fellow actors is what gets him into character as a Darth Vader-worshipping murderer, then so be it. It will certainly be interesting for all of us to see how that pays off in the final film.

Star Wars: The Force Awakens opens in theaters on December 18.