If I was to meet Lou Reed or Bob Dylan, I would be totally helpless. Writers and musicians make me feel completely starstruck. Once I did a read-through in front of Ted Hughes and mauled his text so much I could see him twitching.
I didn't know my blood father that well, but my parents [Robert Stephens and Dame Maggie Smith] taught me that what I do is a job. It's a craft, something you have to work at. My mother taught me that you never deliver a perfect performance. I'm constantly tweaking and fiddling with roles.
Actors don't listen to each other. You're so obsessed with what you're saying or doing that the other person could be talking in Swahili and you wouldn't know.
I've learnt an enormous amount from my children. Mostly that my agenda isn't the most important thing in the world. For a while I was trying to squeeze them into my life. And it was such torment! It makes you realise how selfish you are.
Most actors do stuff they're not proud of to pay the bills – and the good thing is that they do the best they can on it. You know: I'm going to polish this turd and I'm going to make it as shiny as I possibly can.
It's not out of choice that I play so many historical characters. After Pride & Prejudice happened, anyone who looked or spoke in a certain way was shunted into doing that sort of stuff.
I absolutely loved Wolf Hall. I'm intrigued by Henry VIII. He was an utter selfish shit, but you can see why everyone wanted to be around him – people were magnetised. I'm fascinated by those kinds of characters.
The smallest audience I've ever performed to is my three-year-old son on the way to nursery. I'll be babbling to myself in the car and he'll suddenly say: "Daddy, are you running lines again?"
I blub all the time, in the most weird situations – not in the ones that should make me cry. Music makes me very emotional. I think I cried yesterday, in fact.
Danton's Death opens at the National Theatre on 22 July (nationaltheatre.org.uk)