Since Paulo Costanzo's film debut in the college buddy flick "Road Trip," he's noticed some subtle differences in how the public perceives him.

"I'm not a big pot smoker, and I'm not that intelligent - but people want to come up to me and give me pot bags and hang out because they think I'm smart," Costanzo said. "I'm really not like Rubin (from 'Road Trip')."

The Canadian-born actor is struggling, like many up-and-coming big names, with the stress of making it big.

"(Fame) changed my entire life," he said, "and not all for the better. It's hard getting recognized. It's hard to wonder why people want to talk to you. You just have to strengthen your heart and trust people."

Costanzo can now pick and choose his acting roles. He stumbled upon the "40 Days And 40 Nights" script almost by accident.

"When I got the script, I found it in a pile of other scripts," Costanzo said. "I got interested, and I met with the producers - and they ended up casting some really cool actors."

Costanzo plays the antagonizing roommate in the new film, in which Josh Hartnett's character decides to abstain from any form of sex for 40 days in observance of Lent. Costanzo tries to make Hartnett's character give in to temptation.

Given the same challenge, Costanzo waivers on whether he could make such a sacrifice.

"I wouldn't give up anything," Costanzo said. "If I had to, I'd try to give up sex if I was obsessed with a girl or something."

Costanzo thinks there is more depth to the new film than the average youth-targeted film.

"This movie is more of a real movie," Costanzo said. "I think the teen genre is dying down. This film has a distinct style. I'm happy with it; it's got a very big heart."

Using religious traditions in film can be a heated topic, but Costanzo pays no mind.

"I'm not afraid," Costanzo said. "Some people lust for controversy. This film is not intended to offend anyone."

This is not the first time Costanzo has worked with potential offensive elements in film before. His costar in "Road Trip" was the irrepressible fellow Canadian Tom Green.

"Tom's a pretty crazy guy," Costanzo said. "He's much more quiet than people think. He's really quiet until someone says 'Hey! You're Tom Green!' and then he goes and humps a telephone pole or something. He's very funny."

Like Green, Costanzo caught his big break from American casting agents while living in Canada.

"I was out of work in Toronto for eight months," Costanzo said. "I walked out of the ('Road Trip') audition saying, 'I'm the worst actor in the world,' then I got flown to New York and got the part."

Having a recognizable face is something Costanzo dreamed of when he was growing up in Toronto.

"I was a fairly shy and troubled kid who always dreamt of being the kid people looked at," Costanzo said.

Although it's a bit premature to wonder if "40 Days and 40 Nights" might get next year's Best Picture nod, Costanzo offers his choice for this year's vote.

"I hope 'Lord Of The Rings' wins; it revived the whole ethics thing," Costanzo said.

Costanzo is currently costarring in the Miramax Release "40 Days And 40 Nights." It opens today nationwide.