It's your 50th year in the business and you are about to appear as the Doctor in the 50th anniversary of Doctor Who. Both of you have had lots of reinventions. Is there a neat link there?
I'd never thought of that, but let's use it! Oh yes, there's a huge link definitely. But I had no idea that Doctor Who had got so huge; I just thought, "Brilliant, I'll be a Doctor!" I was suddenly – what do they call it? You start "trending". This is all new to me!
Is it a relief you can talk about your role, now that the costume designer let slip to the Prince of Wales that you play a "dark Doctor"?
Of course you have to remember that the Doctors are all one person, so I'm not outside of that. I can't talk about it, but I will say I was really impressed when I did it. Both the previous doctors – Matt Smith and David Tennant – boy, are they good at it. Whoa-wee! They are so quick, and there's a huge amount of learning and no time to learn it in. All that fake scientific nonsense. Terribly difficult to learn.
Have you met the Whovians?
I've done a couple of conferences where you sit and sign autographs for people and then you have photographs taken with them and a lot of them all dressed up in alien suits or Doctor Who whatevers. I was terrified of doing it because I thought they'd all be loonies, but they are absolutely, totally charming as anything. It's great fun. I'm not saying it's the healthiest thing – I don't know whether it is or isn't – but they are very charming.