Earlier this summer, when writer-producer Judd Apatow was promoting his new comedy “Knocked Up,” he was asked by a skeptical reporter if he truly believed that the slovenly character played by Seth Rogen in the movie existed in real life.

Apatow offered to take the reporter to Rogen’s house, where the reporter was assured that he would find that exact character.

Rogen, 25, laughs when reminded of Apatow’s comment, but he doesn’t deny it. In fact, he insists that one would still find an entire house of likeminded guys playing video games, drinking beer and talking endlessly about sex.

Although he is now making millions, the tall, curly-haired actor shows up for this interview on a movie studio lot in his standard outfit – an old T-shirt, wrinkled linen pants and a pair of worn sneakers. He drives an Acura and his only indulgence has been the purchase of a new home. He spends almost nothing on clothing or bling.

He has a deep voice that resonates when he laughs, and he laughs a lot. And why shouldn’t he? The screenplay he started writing at 13 with best friend Evan Goldberg in their native Vancouver has been made into the movie “Superbad,” which many critics have proclaimed to be the funniest film of the year. It opens Friday.

It follows two geeky, sex-obsessed high school friends named Seth and Evan (yes, Rogen and Goldberg named the characters after themselves) during one crazy night as they try to ingratiate themselves with the school’s cool crowd by promising to secure booze for a party thrown by the prettiest girl in the class. Rogen also stars in the film as a funny but misguided police officer.

Rogen, a former stand-up comic and television writer and actor (“Freaks & Geeks,” “Undeclared”), was first noticed on the big screen in “The 40-Year-Old Virgin” as one of Steve Carell’s co-workers, which led to a starring role in “Knocked Up” as the guy who impregnates Katherine Heigl. His next starring role will be in “Pineapple Express,” which he and Goldberg wrote.

ORANGE COUNTY REGISTER: You’ve made a name for yourself by creating the lovable loser on screen. Were you anything like that in high school?

SETH ROGEN: Oh yeah. I was exactly like that. Actually, we showed this new movie to an old high school friend of ours and asked her if Evan and I resembled those young guys in the movie and she said we did, only not as cute.

OCR: Can I assume that you are no longer a virgin?

ROGEN (laughing): Yes, you may assume that.

OCR: So things turned out pretty well for you, despite the sexual frustration in high school?

ROGEN: Things have turned out aces.

OCR: Nothing like a successful film career to take care of those problems, huh?

ROGEN (laughing): That’s right. Although I have had a girlfriend since before “The 40-Year-Old Virgin” came out. I got her on sheer merit.

OCR: How did you do that?

ROGEN:S he somehow took a shining to me.

OCR: Is she an actress?

ROGEN: No, she’s a writer.

OCR: Well, that explains a lot.

ROGEN (laughing): Exactly.

OCR: Did you really start this screenplay when you were 13?

ROGEN: We did.

OCR: To what aim?

ROGEN: We hoped it would turn into a movie someday, but there was no real reason to believe it would. We were just dumb enough to think it could. Besides, it was something to do every day after school.

OCR: Rather than date?

ROGEN: Rather than talk to girls. We’d do anything to avoid talking to girls. We were terrified of that.

OCR: When you left Vancouver and set out on your own to do stand-up, did you put aside thoughts of the screenplay?

ROGEN: We never put aside thoughts of the screenplay. We worked on it continuously since we were 13. It was my other work in show business that made the screenplay more of a reality. It finally seemed possible. After “Freaks and Geeks,” we started trying to sell it.

OCR: What impact did “The 40-Year-Old Virgin” have on your career?

ROGEN: It was huge. I never expected that I would get that kind of respect. I was supposed to be just one of the guys in the movie. And there was no indication that the movie was going to be a hit. Nothing we had done previously was very successful.

OCR: But you liked the movie, didn’t you?

ROGEN: I loved the movie. I thought it was an awesome movie. And I was a producer so I had a lot of fun walking around the set. But I never dreamed it would kick-start my acting career. I never dreamed that what happened to Steve (Carell) off of “Anchorman” would happen to me on “Virgin.”

OCR: When did you get a sense it was happening to you?

ROGEN: While we were still shooting the movie. Judd (Apatow) kept telling me that the studio liked what I was doing. Then we screened it and it got big laughs. But the real sign was when I got a call on my cell phone from Ben Stiller and Owen Wilson telling me how much they liked the movie. That’s the first time I thought, “Wow, things have really changed.”

OCR: What was your financial situation when this big break happened?

ROGEN: I had saved all my money from “Undeclared.” You get paid pretty well when you’re an actor and a writer on a TV show.

OCR: Sounds like you’re a thrifty guy?

ROGEN: I always viewed money as time I could go without working. The more money I have, the longer I could go without working.

OCR: So you must have been pretty confident going into “Knocked Up?”

ROGEN: I’m never confident. I had no expectations. I always assume failure. That’s just how I’m comfortable.

OCR: And what happened after “Knocked Up,” where you were the lead and not just one of the guys?

ROGEN: Oh, that was amazing. It led to “Pineapple Express” and everything else. It meant that from a writing standpoint, Evan and I could do just about anything and, from an acting standpoint, I could put myself in any of our movies. That’s remarkable.

OCR: After a dozen years working on the “Superbad” script, could you ever have imagined it would turn out like this?

ROGEN: No, it’s way better than I ever imagined it.

OCR: Did you ever consider directing it yourself?

ROGEN: We had opportunities through the years to direct it ourselves but it would have been a small independent film, and I don’t really like independent films. I like big commercial movies that are meant for wide audiences. I don’t see the point in making movies that only 10 people will like.

OCR: So, there are no regrets?

ROGEN: Every day on the set, Evan and I would look at each other and say, “Thank God we didn’t direct this movie.”

OCR: Do you think people can identify with these characters?

ROGEN: I hope so. It always baffled us that nobody wanted to make this movie because we believed we had come up with the most relatable movie theme ever. Who doesn’t want to get drunk and sleep with girls? It wasn’t a re-invention of the genre. It was the simplest version of a high school movie.

OCR: What were your favorite high school movies?

ROGEN: “Fast Times at Ridgemont High” was the best high school movie ever, but the opening party scene in “Say Anything” was the most realistic high school party scene ever depicted in the movies.

OCR: They were your inspiration?

ROGEN: Not at all. We wrote our movie in a hateful place (big laugh). We didn’t like most high school movies so we were trying to write one we did like. None of the kids in those movies sounded anything like the way we spoke.

OCR: How did you speak differently than those kids in the movies?

ROGEN: We were much more disgusting.

Contact the writer: 714-796-5051, ext. 1110, or bkoltnow@ocregister.com