I try to work hard. I'm really proud of what I get to do as a living. I still pinch myself. But I also know it's a craft, and I can get better at it and learn every time I do it. So I try to work hard no matter what the task is.

The further you get away from yourself, the more challenging it is. Not to be in your comfort zone is great fun.

There's a huge amount of footage of Julian [ Assange] online, but he's usually in presentation or defending mode, talking about his cause, or the revelations which Wikileaks have brought about. There's none of Assange relaxing or in private mode. There's none of the personality I tried to give him behind closed doors [in The Fifth Estate ].

I'm always keen to use my body in my work, so I'm looking forward to the motion capture for Smaug. Both Gollum and King Kong were primates, whereas I'm playing a serpent, so it'll be interesting - I'll have to tie my legs together, possibly, or else they'll be kind of splayed out to the side as a reptile's should be.

It still makes me giggle that I'm paid to act.

There are moments when, like all of us, you get a bit self-conscious and you'd rather not be living any of your day in public. Those are the awkward times, but you've got to have fun with it.

I think the characters are supposed to be an open book, blank canvas.