I remember a conversation with my parents about who the people on the TV were, and learning they were actors and they acted out this story and just thinking that was the most fantastic notion, and that's what I want to do.

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 think if my eight-year-old self could see me at the Royal Albert Hall winning a prize for playing the Doctor on telly, he would need a stiff shot of Irn-Bru.

I was always going to act, literally ever since I was tiny. In fact, I have Doctor Who to thank for that. I wanted to become an actor after being obsessed with Tom Baker, the fourth Doctor Who, in the 1970s. His was the definitive performance of all time in anything.

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.

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.