I get fans stopping me and telling me what a bad man I am. I got a lot of that at Comic-Con. I'd tell them, 'Sorry, mate.'
I'm not exactly watching my back. Most people, there's a twinkle when they admonish me. And I've watched a lot of footage on YouTube of people's reactions to watching me.
William Hartnell was one of the finest character actors of our time, and as a fan, I want to make sure that I do him justice.