Not a lot of people know this, but I'm very good at mathematics. When I was an angry teenager, I used to sit in my room and do quadratic equations to calm myself down.
'Downton' is one of the best jobs in the world, and I'm looking forward to the next series for Maggie Smith's wicked sense of humour.
Filming is quite exciting because every day is different, but it can involve long hours standing around in chilly locations. Theatre is a very different challenge because every night you're striving to keep it fresh, even though you might have been performing the same play for months.
I lost a girlfriend when I was in my 30s. She was 46. It all sounds so trite, but I put a Post-it on my dressing-room wall. It said, 'The past is history. The future is a mystery. This moment is a gift, which is why it's called the present.'
Something like 'Sex And The City' was insulting - women all clawing on to their youth when there's such ripe territory in honestly exploring women's lives as they get older.
It's always been a dream of mine to be Ginger Rogers or Cyd Charisse, and here I am performing alongside Robert Lindsay and being directed by a major Broadway producer. Who said dreams don't come true?
I've been married to the same man - even after the separation - longer than most people in this business. I'm sick to death of people mentioning it.
I grew up without the rose-tinted look at the profession many of my friends had, but I've been very lucky playing major roles in 'An Ideal Husband', 'Arcadia' and 'The Memory of Water'.
One of my earliest memories is of being about three and a half, climbing through the legs of a man who I didn't know was the famous actor, Patrick Magee.
Agatha Christie holds special personal memories for me because my mum, a television producer called Pat Sandys, had been the first person to persaude the Agatha Christie estate to put one of her stories on T.V.
As a child, I always remember our home, which was a flat just on the Barnes side of Hammersmith Bridge in London, buzzing with actors such as Patrick McGee and Peter Bowles. We were a family who were always on the go.
When I got on stage, I would have a rush of adrenaline; everybody gets it. Normally after the first night it becomes more controllable, and as long as I could ride the wave, I was still in charge.
When women's parts are being written, they are more and more for under 30s who are nubile and beautiful. Actresses over 40 are finding very little happening.