Robert Pattinson expected the 'Twilight Saga' to be a "teen indie" drama.
The actor - who has played vampire Edward Cullen opposite Kristen Stewart as Bella Swann in all five movies in the franchise - expected it to be an "interesting" project but had no idea the series would go on to be a worldwide phenomenon.
He said: "No-one believes me about this. You couldn't buy the books in England and I only knew one person who had read them. It just seemed like it was one of those 'young adult' class reader things.
"I didn't really know how to play it because I thought it was kind of a teen thing - which it did end up being - and I thought, with Catherine Hardwicke as director and Kristen, it was going to be an indie movie.
"It seemed really interesting, a teen vampire movie. I had no idea it was going to be this big thing you'd get on Burger King hats."
Robert also revealed he only auditioned for the role because he needed money to pay a big tax bill.
He told Empire magazine: "I went to LA because I really needed money. I had this big tax bill and I was completely broke."