Blake Harrison, who plays Neil Sutherland in the series and the movie, joked that he and his fellow castmates feel like they may have "peaked" too early in their careers.
On the red carpet at the Jameson Empire Awards 2012, where The Inbetweeners won 'Best Comedy', he told Digital Spy: "We're chuffed. I suppose it kind of has [sunk in], but then I don't think we have any real perspective on how it's done.
"I was saying earlier... the first major film any of us has done has done so ridiculously well, we have no benchmark. We've all peaked in our mid-20s and it's all going to be downhill from here."
Jessica Knappett, who plays Lisa in The Inbetweeners Movie, said: "It's just great to have been nominated for a couple of awards and we're really proud of Laura [Haddock] for being nominated for 'Best Newcomer'. It's all great. We're really excited."
Lydia Rose Bewley (Jane) added: "It's blown all of our minds. We knew it would do well, but we didn't think it would be explosive. The feedback's been marvellous."
When asked if the cast all get drunk when they're together, Harrison replied: "We're all quite reserved really - we're good. When we were filming, we hardly went out on big nights out, it was more a case of having a couple of glasses of red wine with dinner and then off to bed.
"I had one or two experiences when I was younger that I could draw upon. I didn't have to get too 'method'."
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Watch Digital Spy interview the stars of The Inbetweeners on the Empire Awards red carpet below: