Lucky star - Cillian Murphy

How would you describe your character Jonathan in 'On The Edge'?I think he's representative of a lot of young Irish fellas. They have a lot of resources but don't have any medium to utilize them - they're good at things but they just sit around smoking. Jonathan finds himself in the position that when he's admitted to a psychiatric hospital he becomes aware that life is worth living and that there are people who are more damaged than he is.

You got your first big break with when you starred in the stage production of 'Disco Pigs' back in 1996. Was it during the play or after it that you thought you could make a career out of acting?When I packed in law in college it was a great relief. I always felt if I gave it a go I hadn't lost anything because I didn't start off at six or seven years of age going 'I really want to be an actor, I really want to achieve this.' I was lucky because I said 'if I don't achieve anything...nothing ventured nothing gained.' So I gave it a go.

Do you think if you had gone the conventional route, through acting school, you would have ended up in the same place? Or do you think that not having any formal training gave you more of a hunger to succeed?I don't think that actors who aren't trained are in any way more interesting or vital than actors who are. It really is just luck and doing something that catches on and catches the public's attention. Because I didn't go to drama school there were lots of things that I had to learn later - about using your voice on stage and other techniques. It's a means to an end, whether you happen to go and study drama for two years or whether you happen to get a break.

With seven films to your name you're building up a good body of work. Is there a role that you're most proud of?I think that one has yet to come. I think if you become in any way complacent...I always look back and go 'I could've done that much better.' I'm really hungry to improve all the time. I study other actors, look at other actors and think 'if I could ever achieve that I'd be sorted.' I'd love to go back and do more theatre, anywhere, because I think that's where you learn most.

Would you like to branch out into another area like comedy? Would you feel comfortable doing something like that or if someone offered you an action movie? I'd do film, TV, theatre whatever. If it's good that's my whole thing. I don't have any real preference. If it's good work and there are good people involved I'll give it a bash.

Do you feel you're getting stronger with every role?No, peaks and valleys. Sometimes you think you're awful and then when you get a part you think you've done something right. It's the most insecure lifestyle - if I'd know that before I started! I think if you become happy about what you're doing there's no point in doing it. You always have to be hungry to do better.

You were recently the subject of a big two-page spread in a weekend magazine. Do you look at something like that and think it's too much too soon?That piece was very nice but it's like swimming underwater: you come up and that's the reality. You just say 'we'll see what happens.' The main thing is if the audience likes it. If people go and pay £7 and enjoy it that's the most important thing for me.

'On The Edge' is on general release now. 'Disco Pigs' is released nationwide on October 12.