Time has a Q&A up with Rob on their website.

Casting Edward was crucial to the franchise. What did Catherine Hardwicke see in you?

I don’t know. I was a little intimidated by Kristen [Stewart] in my audition. So I played it like a guy who is beating himself up a lot about everything. I don’t think anyone else did it like that. I think they concentrated on the confidence aspect. If you read the book, you know he’s the perfect man, ideal man. If you’re a guy, you have certain ideals about what you think is attractive. And that’s why I didn’t go into it for ages, because I thought I’d end up being silly in the audition. I’d be posing. I guess I tried to ignore every aspect of the confident hero of the story. And I played the extreme opposite. It didn’t end up being that in the film.

If they had cast anyone else as Edward, would the franchise have been as successful as it is today?

I honestly don’t know. No matter how famous I get as an individual, it’s always evened — or even surpassed — by the fame of Edward Cullen. That’s got to mean something. I don’t mind that. That’s just the way it is.

Read more: Time.com