The actor, 80, on childhood stuttering, not doing Twitter, keeping his powers and filming The Irishman

Success isn’t about awards. Success is continuity, a process of discovery. I’ve been very lucky to be a part of movies that were widely appreciated, but there are lesser known movies I’m just as proud of.

A lot of people ask me why I’m always playing violent characters. I feel I’ve never played a violent character; I’ve played characters that were in deep conflict, despair and chaos.

I don’t know where I got the idea to act from. My father used to say, “Where do you come to be an actor? No one in the family is an actor. You can’t sing. You can’t dance.” That’s the way it was in Brooklyn, where everyone was from a family of immigrants. My parents were smarter than me. They knew what it was to be poor. They knew I was heading for danger.

If I hadn’t been an actor, I’d have been a philosopher. As defined by Mel Brooks in History of the World: “Oh, another bullshit artist!” I don’t really know what else I would have done.

When I was a little boy I had a real champion stutter. In time it faded away, for the most part.

I tried Twitter, but I don’t really do that kind of thing. Technology is wonderful. But as innovative as Silicon Valley has been, it’s a runaway train and we need to get a grip.

Fame is a funny thing. The upside is easy access to good restaurants. The downside is the bill! “Movie star” is a nice term, because it’s poetic and fairytaleish, but it has no truth about it.

I don’t do “normal” stuff so much, like going on the subway. I sort of miss it, because you can have interesting experiences. The last time I rode on the subway a man lifted his shirt to show me the bullet wounds he suffered in Vietnam.

Making The Irishman was a bit like a school reunion without the booze! I’ve worked a lot with Martin Scorsese. We have a lot in common in our growing up – me in Brooklyn, him in Lower East Side. That bonded our friendship.

Friendship has been one of the most important things in my life. That love, regard, caring for, being amused by… that something ethereal in friendship is the ultimate.

If I could tell my younger self anything, it would be to broaden my field of study to include more art outside of acting. Writing, for example. In my mind I’m always writing, but I don’t really.

Retirement? No, not really. I don’t think anyone loses their powers as they get older. As long as you’re involved and interested, then you can’t lose it. That’s how I keep being surprised. Old age is actually infused with youthful things. I eat properly, I exercise and I don’t abuse anything. I take care of myself.

The Irishman is available on Netflix now