Steve Carell has been hailed by Judd Apatow for turning The 40-Year-Old Virgin into an enduring comedy classic

Judd, 57, reflected on the legacy of the film during an episode of the Where Everybody Knows Your Name podcast, hosted by Cheers star Ted Danson - saying its success was due to planning with Steve.

The director explained the idea for the 2005 movie originated from a conversation with the actor, now 62, after the actor's breakout supporting role in Anchorman: The Legend of Ron Burgundy.

Judd recalled asking if steve had any concepts for a feature film, and the star pitched a character he had once performed in a comedy sketch.

Judd said: "He was in a poker game, and they're all telling dirty sex stories. And when you get to him, it's clear he's never had sex and he's lying."

The director added he could "relate" to the idea, and from there the project was born.

Ted admitted he had only recently seen the film for the first time.

Watching it with his wife, Mary Steenburgen, he said the pair "howled with laughter", describing it as "such a sweet, loving, raunchy movie".

Judd revealed he had recently attended a 20th anniversary screening of the movie, saying: "I got to watch it, having not remembered about 80 percent of what was in it.

"I was laughing and appreciating how many jokes were in it."

In the film, Steve portrays Andy, a 40-year-old man who has never had sex.

He works in an electronics store, with coworkers - played by Paul Rudd, Romany Malco and Seth Rogen - determined to help him change his circumstances.

Catherine Keener plays his love interest, Trish, with Kat Dennings portraying her daughter.

Judd said: "Steve has such a big heart. At the beginning of the process, we were like, 'What if we took this very seriously, like emotionally?'

"'Not just like a big dumba** movie, like what his problem is, what emotionally he needs to get over his shame, his sense of feeling less than, and his insecurities, and really write to the truth of it'.

"And because he's such a great actor, and so emotionally available, in addition to being the funniest guy ever, he did something really remarkable."

One of the film's most enduring scenes involves Andy undergoing a chest waxing.

Steve endured the process for real, screaming, swearing and shouting now-famous naughty lines.

Speaking to People magazine at the time the film came out, Steve said: "There is something inherently male - I am guessing it is a chromosome we have - that allows us to find joy in other men's pain."

Judd recalled Carell insisting that "the audience wouldn't find it funny unless they believed he was in actual pain".

To mark the 20th anniversary of The 40-Year-Old Virgin, the movie will return to cinemas for a week beginning on 22 August.