Beesley, who penned The Inbetweeners Movie with series co-creator Iain Morris, admitted that continuing the adventures of Will (Simon Bird), Jay (James Buckley), Simon (Joe Thomas) and Neil (Blake Sutherland) at university is unlikely.
"When you go to university, it's a different period of your life and you have to start thinking more carefully about your impact on the world around you," Beesley told Empire.
"Here, they're at this glorious age where they do what they like and no-one picks them up on it. They go out into the big, wide, real world, learn some lessons on the way and do a bit of growing up. This is the final piece of the jigsaw."
Watch the Inbetweeners Movie trailer below:
Morris admitted that he hopes the big screen spinoff is able to sustain itself over a feature-length running time.
"For 25 minutes you'll stay with people because they're idiots and they're making you laugh," he noted. "But my experience of watching films is that you have to give audiences something to hold on to, to help you stay with them."
Beesley cited The Simpsons film, South Park: Bigger Longer & Uncut and In the Loop as recent examples of successful TV-to-movie adaptations, saying: "There have been more successes than failures. The failures tend to be from the 1970s, and most of the people who tend to write about them are of a certain age and remember those.
"Wayne's World is brilliant at taking sketch characters and then making people really care about them."
The Inbetweeners Movie opens in cinemas on August 19.
Watch the stars of The Inbetweeners discuss the movie with Digital Spy below: