Guy Pearce was apprehensive about working with Robert Downey Jr.

Los Angeles: Australian actor Guy Pearce, who has shared screen space with Robert Downey Jr. in ‘Iron Man 3’, says he felt nervous while working the Hollywood star.

"I was a bit nervous that he might have been a bit of a firecracker and he was never going to listen to anything anyone said. I thought, `Wow, this guy`s a genius, he`s not even going to notice I`m there.` But it was the complete opposite," quoted femalefirst.co.uk while saying. "And it`s not like he`s sold out and he`s playing some schlocky superhero and he`s doing it badly," he added. IANS