11/07/2012 04:43 pm ET Updated Nov 08, 2012

Judd Apatow Reveals He Wrote A Spec Episode Of 'The Simpsons' In 1990

With his upcoming film "This Is 40," his work as a producer on "Girls" and a library of classic blockbuster comedies like "Knocked Up" and "Bridesmaids," Judd Apatow has established himself as one of Hollywood's leading behind-the-scenes funny men.

But the writer and director came from humble beginnings. Apatow revealed in an interview with Slash Film that his first writing project was a spec script for an episode of "The Simpsons."

"The first thing I ever wrote was a spec episode of 'The Simpsons ... After only five 'Simpsons' episodes aired, I sat down and tried to write one when I was in my early twenties. And what it was about was they went to see a hypnotism show and at the hypnotism show, they made Homer think he was the same age as Bart.

And then the hypnotist had a heart attack. So now Homer and Bart became best friends and they spent the rest of the show running away because Homer didn't want responsibility and didn't want to be brought back to his real age. So I basically copied that for every movie I've made since."

"The Simpsons" may have been good practice for his TV career as well. Apatow created "Freaks And Geeks" in 1999, starring James Franco, Jason Segel, Busy Philipps and Linda Cardellini. And according to Philipps, all four actors owe their success to Apatow.

"Even though we were all relatively young and mostly inexperienced, [Apatow] validated our ideas and talent by always giving us room to collaborate with them even at age 17, 18, 19," she told HuffPost TV. "It's invaluable to get that kind of confidence just in the beginning of your career -- that you know what you're doing."

"This Is 40" hits theaters on December 21.

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