The bravest thing I've ever done is fly to New York. I'm simply terrified of aeroplanes - I am the woman you see weeping at the airport.
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.
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'm an appalling flyer. I get very tense, although I no longer weep uncontrollably for no reason - I just sob if there's turbulence.
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?
'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.
If I pop off and do something drastic, everyone's going to realise because they know I'm 50. Anyway, middle-aged women are sensational.
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.