HE may be a world famous director, but it seems Sam Mendes isn't perfect after all.

Speaking in front of a sell-out crowd at Magdalen College School, the face behind recent James Bond films Skyfall and Spectre confessed he may not have been the ideal pupil.

Despite being an alumni of MCS, the audience were shocked to learn Mr Mendes had been given a U grade for his Maths O-Level – twice.

He said: “I loved this school and I had a great time here. I wasn't academically very strong though.

"I came to directing late. I did not really know what I wanted to do when I went to Cambridge to go to university."

During his hour-long talk on Friday, as part of the Oxford Festival of the Arts, the 50-year-old spoke about his early years directing for the Royal Shakespeare Company, his move into making movies and what it is like to work with 007 star Daniel Craig.

He also opened up about what it takes to be a great director, and his favourite actors and actresses to work with.

The audience laughed when he told them that during the filming of 1999 Oscar winner American Beauty, he found star Kevin Spacey on the phone to a friend between takes.

He said: "He left his phone, still on the line, on a table while he came to film the scene. He then went back to his phone and started talking again. It was amazing."

When asked about working alongside such famous faces, he said: “Here actors are dealing with a huge level of movie stardom and you are dealing with that all the time.

“You can become very stressed and very tense.

"With someone like Daniel you have to focus all the time and it's really not easy. You might be out in the public filming a scene, like in Mexico City when you have 30,000 extras around you.

"As a director as well you might have to keep your concentration up over 14 hours in a day. That might only mean you get 30 seconds of film, say if you are filming an action scene as well."

The Oxford Festival of the Arts finished on Saturday.

Other speakers included broadcaster John Simpson and former Olympian Roger Black.

A new production of The Wind in the Willows at Oxford Playhouse was the highlight of the drama programme and there was a production of Shakespeare’s Love’s Labour’s Lost beside the Cherwell.