It's very hard to be objective about something you're in, especially when you set it up against things that you experienced as a child.

Back in 2005, when I was Christopher Eccleston, we saw one of the largest increases on record, of CO2 in the atmosphere. Unless we keep the rise in global temperature to under 2 degrees, by the time I'm Daniel Radcliffe or wee Jimmy Crankie, I won't be able to save the planet. I won't be here to help you -- well I might, but I'll be that bloke who won Any Dream Will Do.

I love characters who are clever and smart, and you have to run to catch up with. I think there's something very appealing and rather heroic in that.

I think it would be self-indulgent to go, "Oh, I'm going to make this character different by giving him a quirk of some kind." I don't think that serves the story, particularly. But even very similar scenes with a different set of actors, a different set of circumstances, it starts to evolve as a different character.

I mean, you know, while I'm acting on stage I'm ranking quite high, but in a room with Barack Obama I'm probably into negative digits. I never feel very famous.

Getting the call to be in The Goblet of Fire was like being welcomed into the most exclusive upper circle of some elite actors' club. You sit on set with the cream of the National Theatre and the RSC, all clutching wands or wearing witches' hats.

It has to be said that the bad guys are often more interesting than the good guys because you get to indulge part of your nature that hopefully gets subsumed most of the time. But I just like playing interesting characters, and variety's the spice of that, as it is with life, I suppose.