Ours was a family that got shit done. My grandfather was America’s Secretary of War, previously the governor of Utah. My dad’s law partner – my godfather – ran for the presidency, twice. Every week important people joined us at dinner. What I saw put me off politics for life.

At 14, my parents sent me to a boarding school in New England. My protest was the longest conversation I ever had with my father, and it only lasted 20 minutes. Later, I realised they just wanted me out of the way.

I’ve been a runner since the age of 11. For 17 years I ran without ever missing a single day. It was an addiction, really: seven to 10 miles, come rain or shine.

I quit college after two years in 1956 and started going to the movies almost daily. I realised how profoundly the people I watched were touching me. God, I thought, I’d like to learn how to do that. I packed my things and headed to New York.

I spent my first year learning to act in silence, focusing on character and expression without uttering a word. It taught me that acting is the ability to be publicly private. Jack Nicholson calls it a “Dernsy” when actors add material that’s not on the page; Quentin [Tarantino] says on screen I’m always “in the now”.

I’ve never had a drink or smoked a cigarette. My parents were what I’d describe as social alcoholics; it put me off. In the 90s, however, I got hooked on Vicodin – a prescription painkiller. For five years I was popping 27 pills a day.

Awards never bothered me much. That changed the year my daughter Laura was nominated for her first Oscar in 1992. Her mother – Diane Ladd, my ex-wife – received a nomination for the same movie [Rambling Rose]. I was incredibly proud of them.

Endurance has been key to my longevity in the industry. If you want to succeed in any craft, you have to be patient. Only conventional people make it early. The rest of us have to work hard to create a space for ourselves.

Laura and I just shot a series, Mrs American Pie, where I play her father. We didn’t write the dialogue, but it was exposing. In front of the camera, we confronted real life.

Diane and I had a child who drowned in 1962. It was horrific. Ten years later, when I was driving Laura, she said: “Daddy, I miss my sister.” Her sister had died five years before she was born.

Retirement is impossible. Acting is what I do and who I am. I’ll keep at it as long as I can. I can’t remember lines as well as I used to, but I’m good enough.

Silent Running is available on 4K UHD Blu-ray from Arrow Video