What's not to look forward to? It's like all the actors in all of the films. It's difficult to get Martin Freeman and I in a room together. Imagine what it's like to get myself, Chris Hemsworth, Robert Downey Jr., Elizabeth Olsen... these extraordinary actors who all have careers outside the Marvel Universe.

I always get self-conscious about what I look like in a film, but less so if I'm a character very far removed from who I am. Then I just worry about the performance, and that's equally an odd experience.

I remember very clearly someone saying, 'Don't shake hands with the cactus,' and I thought, 'Well, why not? What could possibly go wrong?' Shaking hands is a friendly gesture.

Sometimes during a conversation with a journalist - where you are answering things you never normally talk about, not even with some of your closest friends - you end up being quite confessional, and you don't think about the amplification of that. No matter how fancy these journalists are, they have editors or political leanings behind their publications, which means that, basically, they're going to shape what you've said into an article they've already written. So you have to be really careful with your words.

My own grandfathers were a submarine commander and a 'desert rats' tank operator in the Second World War.

Kevin Feige said to me: "I don't think we've ever put an actor through quite as much as this, physically and mentally." I'll wear that as a badge of honour. It was endless.

I'm not confident in social situations; just going up to someone in a bar and saying 'Hi' is going to be even more difficult because they won't know the real me. They will just know me as a fictional person I play on the screen.