Pitt also admitted that he felt “a little giddy” as shooting for the film got underway over the British GP weekend, including sequences involving him driving the production’s F2-based car in between real sessions.
The Hollywood star gave his first extensive insight into the movie and its plot in an interview conducted in the film’s Silverstone garage by Martin Brundle for Sky Sports F1.
"I'm a little giddy right now, I’ve got to say,” Pitt told Brundle. “And it's just great to be here, man. We're just having such a laugh, such a laugh. It's the best time of my life.
"Listen, it's all been great. I mean, the vibe is amazing, you know that, but just to get to be a part of it in this way, and get to tell our story, and everyone's been really cool with us.
"All the teams have opened their doors for us, the FIA, Mohammad [Ben Sulayem] has been really helpful. And F1 Stefano [Domenicali], everyone has just been really, really amazing, that we can do this. And it's going to be really good."
Pitt gave an outline of the story, which sees him play a long-retired driver returning to the current grid.
"I would be a guy who raced in the nineties,” he said. “In fact, I would have been on the track with you at some point!
“He has a horrible crash, kind of craps out and disappears and then is racing in other disciplines. And then his friend played by Javier Bardem is a team owner.
“They're a last place team, they're 21 and 22 on the grid, they've never scored a point. And they have a young phenom played by Damson Idris. And he brings me in as a kind of a Hail Mary. And high jinks ensue.
“Tell you what's amazing about it. You'll see the cameras mounted all over the car. The shots, you've never seen speed, you've never seen just the G forces like this. It's really, really exciting."
Pitt said he had no prior experience of racing cars before his training programme started, although he has ridden motorcycles: “More bikes, I spent the last 20 years on bikes on track. That helped a lot.
"It's really humbling. I mean, I don't know if you can call mine a hot lap. I call it kind of a warm lap! I've taken a few tours, unintentionally, through the grass. But it's just been such a high.”
Asked by Brundle if he had hit anything hard yet, Pitt said: “Only my ego!”
Pitt insisted that he wasn’t nervous about driving round Silverstone in front of a full crowd.
"No, I really wasn't," he said. "I mean, the guys really prepared me well. And there's a couple of corners, I can see the stands.
"On the straights, you have a little bit of time to kind of look around, but I'm really, really focused on the lines, and what we're trying to create in these moments.
“For us, I want to say for all the armchair experts out there, you've got to give us a little breathing room. If you see any spinouts or something that looks like it's a stall or something like that, it's by design, okay?"
Pitt stressed that he wanted the film to be realistic.
"We've got Trevor Carlin's team,” he said. “And they've been sensational, in keeping us safe and training us and really operating the show, like the real thing. It should be as authentic as we can get it.
“And Lewis [Hamilton], who's also our producer, is really, really intent that we respect the sport, that we really show it for what it is.”
Pitt concluded the chat by paying tribute to Brundle and racing drivers in general.
“I’ve got to tell you, as a civilian, I had no idea what it takes to be a driver and the aggression and dexterity," he said.
"They're amazing athletes. I've got so much respect for everyone out there in all classes.
"I'm going to be here till they kick me out. Because I'm loving it. I think it's every guy's dream.
“My character would have raced in Le Mans, he would have raced in Daytona. I saw you won Le Mans, you won Daytona. I just thought it was stellar.
“Again, I have so much respect what you guys do, and I've been enjoying your stuff for years. So thank you! It's really great to be here."
