I really enjoy playing mental cases, people with obsession and delusion. It means that as an actor you are engaging your imagination all the time.

I used to be a bit too humble for my own good. I had to learn self-worth and to have a positive image of myself. Maybe it’s a good thing. Perhaps if I hadn’t been humble I’d be really fucked up now.

I don’t think it would be a bad thing if Scotland went independent. It’s going to happen now – we’re on the path – it’s just going to take a wee bit longer. It’ll be an amicable divorce rather than a messy break-up.

In large part I was raised by my grandparents. They taught me a respect for people, a respect for money. Money is freedom. From them I absorbed the importance of owning your own place and not owing money or having credit card debts.

Since becoming a parent I no longer blame kids for bad behaviour. I blame the parents. I don’t want to spank the kids; I want to punch the parents.

I was raised a Catholic but the minute I was allowed to make my own choices I stopped going to church. I wouldn’t take my kid until he wanted to go.

We’re living in an increasingly non-religious environment and superheroes are our gods at the moment. They’re like the Norse or Greek gods: unreliable characters with incredible powers. What’s fun about them is that they’re already consciously an allegory. God is never an allegory.

I’m a classic middle-class drinker. You can go through a month and realise you’ve had a drink every single night – not a large amount, but not a tiny amount either. And I say I don’t smoke, but I do. All actors have too many cheeky tabs.

When you’re growing up, a football team can help you identify yourself: you literally put a badge on your chest. But being a Celtic fan is hard. You get the incredible highs, like beating Man Utd or Barcelona, but then the low-level depression when you get humped.

Recently I have been thinking more about death. Perhaps it’s because I’m 36 and I might be halfway through my life. It’s not all that unusual for a guy to die before he’s 70.

My son is going to have loads of money and a better education than I have. But the opportunities should be there for every child to do as well as my kid. It feels like the educational situation’s getting worse and the poles are growing further apart, which doesn’t feel fair in a country that’s meant to be democratic.

When I first met my wife [Anne-Marie Duff] on the set of Shameless, I was like: “Why do I fancy you, apart from the fact that you’re really fit?” Then I realised I’d had a weird woman-on-the-telly crush on her when I was 18 and she was in Aristocrats.

James McAvoy is in Victor Frankenstein, released in cinemas on 3 December