The cast of Kung Fu Panda 3 on what they wanted to be when they grew up

I always wanted to be a piano player. I grew up studying piano, particularly jazz. I just didn’t have the talent. I had the desire, I had the feeling for it – and I still have it – but I didn’t have a very good ear. I couldn’t just sit down and play something if you whistled it, like many musicians can. I could not read regular classical music quickly; it was all laborious for me. I still feel I missed my calling in life. If God said today, “You will be what you always wanted to be starting right now, and that is a really good jazz pianist,” I’d quit everything and be quite happy.

I was a bad student, I couldn’t concentrate, I was always daydreaming, and I didn’t have the grades to get into university, so I went to a junior college. I was failing the first year, when a friend said, “Why don’t you take an acting class? No one flunks acting, it’s like gym.” That’s the reason I took it. It was the first time that I took any class, or tried to do anything, where I didn’t get frustrated or bored.

When I started studying acting, I had friends who were as unsuccessful as I was. We were all doing different things – Gene Hackman moved furniture up and down tenements, Bob Duvall worked in the post office midnight ’til one in the morning, and I waited tables.

You just have to be lucky. When I did The Graduate, I was extraordinarily lucky. I had the best American director that existed then, in a terrific screenplay that they had spent two years writing, with a wonderful cast. That doesn’t come by that often. I hit the lottery.

But I constantly have doubts, and that never changes. It’s so subjective. A comedian gets on stage, and if he gets a laugh, it works. But you don’t have that feeling as an actor. You don’t know. Usually there’s no sense of it.

I have a son who teaches yoga and composes music and has a serenity that I feel I’ve never had. One of the themes of Kung Fu Panda 3 (in cinemas Friday 11 March) is that they use the word “Chi”, in other words finding your inner self; the purpose of life is to find your inner self. Your essence. And I think you spend a lifetime doing that.

Teacher — Jack Black, 45

Known for The School of Rock. He’s also lead singer in comedy rock band Tenacious D.

One of the great themes of Kung Fu Panda 3 is the relationship between teacher and student, and what it means to be a good, effective teacher. That struck a chord with me because if acting hadn’t worked out, I probably would have ended up teaching; it would have been a way to earn a living and stay in the arts. Trying to turn the student into the best of themselves and nurturing the next generation is a big responsibility.

But I knew I wanted to be an actor very early on, and at 13 years old I got an agent. My step-father drove me to auditions and my biological father was also very supportive. There were a lot of people telling me they were proud – I couldn’t have done it without that.

I know some people respond to that Whiplash kind of teacher, where they’re really cruel to you. But that was not for me. There’s a lot of ways to teach;I just hope I can do the same for my boy.

Make-Up Artist — Kate Hudson, 36

Rose to fame in 2000 for her Oscar-nominated role as Penny Lane in Almost Famous.

I was always very into fashion – I love clothes and design, and I love make-up. I’ve always said that if acting didn’t work out, I’d be a make-up artist. I love doing my friends’ make-up and I do my own a lot of the time, too. Really though, there was never another option.

The moment I realised I had to act? It happened when I came out of the womb, that’s what my mom says! As you get older and have kids, you realise what people mean when they say it’s in the DNA. I really think musicality and performance are in my genes. I look at my niece, Rio, she doesn’t know what our family are from a hole in the wall, but all she does is perform. She takes it so seriously... she’s two years old.

The defining moment for me was going to Williamstown theatre festival when I was 16. I was signed, sealed and delivered from that point on. We would go to acting class, we’d go to movement classes, we’d build sets, we’d create plays and productions and put them on in the middle of a field. I always thought I’d be more of a singer/dancer on stage, but the second I started auditioning I got jobs, so my career took me the way it took me.

Everybody has moments where they think “can I do this?” That question fuels some people, but freezes others. I’m a performer, so it fuels me. I feel women struggle with this more than men, though. We judge ourselves really harshly. It’s important that we stand next to each other. Female competitiveness has become such a part of our society but the reality is that one woman’s success is another woman’s success, and another woman’s future success. The first step to that is just feeling good in yourself, period.

Policeman — Bryan Cranston, 60

Best known for playing chemistry teacher-turned-drug lord Walter White in Breaking Bad, he was Oscar-nominated for Trumbo.

I was going to be a policeman. I was a member of the Police Explorers’ group – a part of the LAPD – and I was studying police science. I was actually pretty good at the work. But then I took an elective course in acting and discovered there was a tremendous amount of fun to be had. I thought, “Wait a minute, this is fun, the girls are pretty, I like this...” So I started to veer away from the police work and into acting.

My father was an actor, and he lived the typical life of ups and downs. I knew the reality of it – it’s tough. But witnessing that helped me when I was starting out; there was never a delusional quality to the career. I said to myself, “There may be actors that are better than me, but no one can outwork me. That’s something I can control.”

Everyone doubts themselves at times – but hopefully, you have more moments of confidence than of uncertainty. The breakthrough for me was when I was around 25 years old. I moved to New York to do a soap opera and there was an energy that changed in me – suddenly I felt like I belonged, I knew that I could do it.

I realised then, that we go from listening to stories as children, to becoming the storytellers. What a marvellous transition that is, and what a gift, to be charged with telling those stories for a living.

Actor — JK Simmons, 61

Won an Oscar, Golden Globe and Bafta for best supporting actor in Whiplash last year.

It was really my lack of other saleable skills that made me become an actor. That and a combination of falling in love with storytelling, and realising there were lots of chicks in theatre. That was definitely an aspect of it as well!

But if you’re foolish enough to try to have a career in this business, you’re going to face rejection repeatedly. There was one time, when I had no job and no prospects – I couldn’t even get a job waiting tables or tending bars, those “survival jobs”! – I remember talking to my mom about alternatives and it turned out I didn’t have any. I was either gonna have to keep going, or become a much better waiter.

I was doing theatre for the first 20 years all over the country, followed by a few years on Broadway. Dustin Hoffman as a fairly young man became a very well-known film actor and a brilliant one, and he was among my inspirations as a young actor. I was gonna say “struggling”, but I wasn’t struggling, I was having a great time in those early days. It occurred to me that I would end up being a film and television actor, I was just happy occasionally getting paid to be in a play.