The 67-year-old said she was scared of certain actors in the industry, reported Contactmusic.
"When I came into the acting profession it was quite hierarchical unlike today. You didn't sit at the same table as the leading actor. It was coming out of that 50s period, Lawrence Olivier, John Gielgud were very, very intimidating and powerful people," she said.
Mirren who gone on to enjoy an incredible career and has won numerous awards including an Emmy, Golden Globe and a Best Actress Oscar for her portrayal of Queen Elizabeth II in 'The Queen', now realises she can be intimidating too.