Audrey Niffenegger penned the best-selling book the hit film, starring Bana and Rachel McAdams, was based on.
The author admits she didn't think the Australian actor would be right for the role - and had envisaged the part going to The Pianist star Brody.
And Niffenegger was so terrified about seeing her tale on the big screen, she has so far refused to watch it.
She says, "Once I signed away the rights, I just had to let go. Once you sign on the dotted line, you have no control... I decided it would probably be best if I just (didn't see it)."