Bradley Cooper, star of The Hangover and The A-Team, headlines his first solo movie LIMITLESS, a superlative action thriller about a failed writer whose life is turned round by a top-secret drug called NZT which allows him to access all areas of his brain.

Cooper talks about working with Robert De Niro, getting up to speed with his character Eddie Morra, and why making a movie is like running a marathon.

Limitless opens on 23rd March.

Q. You’ve enjoyed huge success in The Hangover and The A-Team as part of an ensemble of actors, but Limitless is your first big solo movie. What did it feel like to be carrying a film?

Cooper: I didn’t feel any added pressure. I think I would have felt tremendous pressure if I’d shown up to work unprepared. The narrative is completely dependent upon Eddie Morra. And playing Eddie in all his evolutionary stages demanded a lot of work. If I’d shown up without really having done the work I would probably have had a panic attack and been put in to a hospital because there wasn’t much time and we shot it in 38 days!

But making a movie’s like running a marathon. With The Hangover or A-Team, I felt that at the starting line I had Rampage [as BA Baracus], Sharlto [Copley as Murdock], and Liam [Neeson as Hannibal Smith], and we were all running and we passed these little towns. And in this town there was Jessica Biel, and we passed through another place.

And it’s the same thing with The Hangover. There’s Zach [Galifianakis], me and Ed [Helms], and then we’re running and there’s Justin Bartha, Heather Graham… But in Limitless, I’m by myself running the race and I pass a town where Robert De Niro is. So that was much different.

It’s also an opportunity to really bond with your director. It’s you and your director in the trenches together, which I love. I just can’t get enough of that.

Q. You work with Robert De Niro in Limitless. Was that scary?

Cooper: It wasn’t. Now, that could be because my relationship to De Niro predates the movie… at least in my mind! [Laughs] The first movie I saw of his was Raging Bull and before I met him I thought, ‘God, his hands are just like my grandfather’s.’ I didn’t even know he was Irish-Italian, and I’m Irish-Italian, but he reminded me so much of my family.

I always felt a real emotional connection to him and his work. He was one of the first actors who made me cry when I watched him. Then he spoke at our school and I got a chance to ask him a question in 1998, and then I put myself on tape to play his son in the movie Everybody’s Fine, which he saw the tape of. And I got a chance to meet him in a hotel room for all of about 15 minutes ’cause he saw the tape.

Then I was a juror at the Tribeca Film Festival so I saw him around and I’d catch him walking in and out and actually sat and had lunch at a big luncheon with him. He was at the table and I said, ‘Oh hey, Mr De Niro, we met last year for a film’, and he said [does De Niro impression]: ‘This Boy’s Life?’ And I thought, ‘This Boy’s Life? I would have been 12! He has no idea who I am!’

But the story continues: a year later I’m in his hotel room pitching him an idea to play a character in a movie that I’m doing, so it’s a very odd turn of events.

Working with him was the most effortless experience I’ve ever had acting. He is a wonderful human being and very generous. He’s been doing this for 40 years and his level of excitement and willingness to work on the day in the scene is unparalleled.

Q. De Niro’s character Carl Van Loon gives a speech to your character Eddie, telling you that you’ve just arrived on the scene and you’re trying to be on the same level as him and adding that, unlike you, he’s done all the work to get where he is and has the background. Did that resonate with you at all?

Cooper: God, you really hit it! He’s basically saying I haven’t earned anything… and I’m thinking, ‘have I not earned this?’ I really did think that! Then I thought: he’s looking right at me! And I don’t think he says ‘Eddie’ in that speech.

At one moment when we were looking at each other, I honestly felt that thing you feel in life when somebody says something awful to you. And I thought, ‘Oh my God, he really thinks that. This is Robert De Niro’s chance to tell me that he thinks I haven’t earned anything.’

And it was really crazy and I thought, ‘God, he’s such a fucking good actor’, ’cause he made me feel that way which is exactly how I should feel because that’s the scene.

Q. You talked earlier about the preparation you had to do for the role. And you really did have to get up to speed, quite literally, to play Eddie as everything is so fast paced in both the way he talks and takes things in when he’s on NZT. So how did you go about doing that because you have to talk very quickly and very precisely in single takes?

Cooper: I remember reading how Ben Kingsley worked on his role in Sexy Beast by running and saying his lines at the same time. I had a script a while before we shot, maybe four, five months, and there were whole sections that I put to memory very early on and I would just say it throughout my day all the time, like the half-page speech where I woo De Niro’s character in the dining room.

Neil [Burger, director] chose to shoot all those big chunks in one take, so there was no room for cutting. We had to do it 25 times, like that [snaps fingers]. And it wasn’t like, ‘let’s just get one where you say it all right and we’ll use that one.’ It was, ‘you’ve gotta say this right 25 times because there’s a lot of moving parts that aren’t working.’

So I would do what I felt good, but then someone was in the light so we’d have to do it again, and then the camera hit the guy, so we had to do it again. So thank God I’d put that all over to the side already so I could just be Eddie.

But I also love that [speed] because I speak fast as it is in my life and more often than not I’ve had a direction from a director saying ‘just slow down’. So when I read the script I thought, ‘oh, I don’t have to slow down’. [Laughs]

Q. One of the ideas in the movie is that everything we hear and see in life is useful and that it’s kept locked somewhere in our brains. What did you draw on from your own experience?

Cooper: I was definitely faced with the dilemma of how to make this real for myself, so that I’m not acting it, I’m not affecting it on the day because that would be brutal to do and very brutal to watch. There’s nothing like bad theatre. It’s the worst thing in the world when you’re watching someone act, especially if you’re watching someone try to act smart! [Laughs]

So I took it completely out of the world of that ’cause I thought: even if I read up on neurological science for the next 4 years, it wouldn’t give me any meaty material to turn in to an organic expression which would make you believe I’d changed or opened up the synapses in my brain.

I went to a completely different place of something I thought would move me in a way that by expressing it you’d think I’d taken that drug. Without saying what it was, it was just really personal, specific things, but it definitely was a huge awakening for me and one that was organic. That’s my way in…

When we first started shooting and we did Eddie on NZT I was doing him a little like a cyborg. There was a little mechanical aspect to it. And I remember watching playback with the director and asking ‘how much of the movie am I on the drug?’ And he said, ‘quite a bit’. And I thought, ‘I’m bored and I just watched half a scene.’ [Laughs]

Then I thought, ‘wait a second, he’s on the drug so he’s smart enough to know he doesn’t have to act like a robot!’ [Laughs] That’s just my brain thinking he’d talk like that and move like this [does robotic movement], which makes no sense at all! In fact he should be the opposite as he’s so smart. So we got rid of that early on! [Laughs]

By Jan Gilbert, Freelance film journalist (www.jangilbert.co.uk)