I grew up in London, one of four children. We were a very loud family, not a lot of listening, plenty of talking. My mum was a hearth mother, she loved to gather us all around her – Sunday lunches were a big thing. She was very good at thinking on her feet – people used to say she should go into politics.

My dad has always been very theatrical. He never worked in the theatre – he’s always worked in insurance – but in another life and another time, he could have done that. His love of the theatre meant I was always going to shows and plays as I was growing up; and then I started acting at school.

I went to boarding school from the age of eight – first to prep school, then to Eton. One thing that kind of education teaches you is community living: there’s little retreat. That’s why people come out of it and talk about lifelong friendships forged in the furnace. The cut and thrust of a successful school can be very bonding. I was always encouraged to be on teams at sport; I got a lot from that. Would I send my son to Eton? I might.

My parents came to see me in a play at Eton when I was 16. And then, when I said I wanted to try for drama school, they knew there was enough passion there for them to be brave and back me. Both of them said: “Go for it.” I remember my mother saying: “I’d rather you went to drama school to do something you love than go to university and get a second-rate degree in something you haven’t loved doing.”

My background was fairly conservative and I think there’s a strong notion of duty in a background like that, and I don’t think that’s always helpful. As you live your life, what comes into sharp focus is the choice between duty and what you need to do for you. So I wouldn’t want to impose a sense of duty on my children, but I think a sense of honour is always important. It’s about behaving honourably when making choices – being careful over them, making a considered choice.

I say to my children [Manon, 10, and Gulliver, nine] that sometimes in life there are tough moments: you may find yourself on one side of the room and everyone else is on the other. It might be easy to head across to where they are: but if you believe that what you’re saying is right, be courageous, because that’s the right thing to do.

My dad used to say: “No one expects you to be the best at everything. All we expect is that you try your best. Because if you don’t try your best, you will be disappointed.” That message gives you a sense of competition with yourself, it drives you on. I think it’s quite a clever thing to tell someone.

My mum used to say to us: “All I care about is that you’re kind and thoughtful.” But my dad was more transactional, he used to say: “You cooperate with us, and we will cooperate with you.” I say that to my own children.

A big sadness for me is that my children didn’t get to experience my mother as a grandmother [she died in a car crash in 2001]. She would have been amazing. She just saw the beginning [of my success] … she came on the set of Band of Brothers and met Tom Hanks. She was aware I was being asked to do a rather amazing job and that I was heading in a certain direction. She was incredibly proud of me.

My mother used to say two things to me: “Make sure you get married before you’re 35,” and: “Don’t marry an actor.” But she would have been over the moon with Helen [McCrory, an actor] whom I met when I was 36. There’s a sadness for me that these two strong ladies never met – there would have been a real buzz between them.

• Damian Lewis is supporting the Sohana Research Fund, sohanaresearchfund.org. He is appearing in The Goat, or Who is Sylvia? at the Haymarket theatre, London until 24 June.

• This article was amended on 18 April 2017 to correct a date from 3 June to 24 June.