The tricky thing becomes: Do you know yourself well enough to then portray that on screen? And for me, I find that really hard. I'd rather hide behind accents and funny walks.

The biggest difference for me is momentum. On a smaller film you get to shoot sometimes four or five scenes a day and you've got to do the tight schedule. I think I really feel the luxuries of a big budget film.

I always kept myself fairly fit.

Whenever you deal with science fiction you are setting up a world of rules. I think you work hard to establish the rules. And you also have to work even harder to maintain those rules, and within that find excitement and unpredictability and all that stuff.

There's the pressure of being a No. 1 on the call sheet, being a lead actor. There's almost this feeling like being captain of the team. You want to put a bit of energy into actually setting a good example.

Whereas 'Avatar' and other movies get shocks out of their three-dimensionality, 'Gatsby' is going to be about inviting the audience into this larger-than-life drama, letting them almost be inside the room rather than looking at it through the window. I think it will really work.

The Great Gatsby' ticked so many boxes for me.