HOLLYWOOD -- Two big stars -- [movieperson id="256873"]Bradley Cooper[/movieperson] and [movieperson id="8456"]Sandra Bullock[/movieperson] -- were the main attraction Tuesday night at Mann's Chinese Theatre, as they walked the red carpet for the premiere of [movie id="354663"]"All About Steve."[/movie] One is brand-new, the other is a veteran, and both were eager to celebrate their new romantic comedy.

"He's an actor's actor in a movie star's body, and I think he'll always remain firmly grounded and not get too full of himself," Sandra Bullock insisted, glancing over at her co-star Bradley Cooper, a.k.a. the hottest actor of the summer thanks to "The Hangover." "He loves to work ... but he's just as humble now as he was back then."

The 'All About Steve' Premiere Red Carpet

Back then is when "All About Steve" was filmed, at a time when Bullock was the movie's big star and Cooper could best be described as "that guy from 'Wedding Crashers.' "

"It wasn't rocket science," the film's director, Phil Traill, said of casting Cooper before he became a household name. "He came in, and he gave the best audition. Creatively, he gave the best audition, he looks good and he's really funny. His name didn't make a difference -- he acted the best and was the funniest."

These days, Cooper's name means a lot -- he's already attached to such high-profile films as a "Hangover" sequel and a big-budget "A-Team" movie. "I'm really excited for Bradley," explained Traill. "And I know it's a good thing for our film that people know who he is."

As for Cooper himself, he said that no matter where his own career stood, he was just happy to be in a film opposite rom-com icon Bullock. "I was expecting kindness and generosity, and I got nothing but a tyrant. She was a nightmare!" he joked, teasing his leading lady. "No, she was very kind, lots of support, always asking, 'What do you need?' Really just very supportive and always helping me out. It got very old, very fast."

By now, you might be wondering about the film's plot -- which involves a quirky, lonely crossword-puzzle writer and the handsome cameraman that she falls head over heels in love with. But according to Bullock, giving anything more away would take as long as the movie itself.

"I could not begin to tell you about the plot of the movie, because we'd be here for one hour and 35 minutes," she reasoned. "It's not that it's complicated, but if you had to summarize your life in one sentence for the media, could you? You have to go on the journey. My question was: What is normal, and why do we keep insisting that people be that?"