Bradley Cooper delayed directing a movie because he was ''terrified'' by the idea.

The 43-year-old actor has made his directorial debut with the new musical romantic drama 'A Star Is Born', which features Lady GaGa, and although Bradley has always harboured ambitions to direct, he's also been reluctant to take the risk.

He confessed: ''I always knew I wanted to direct since I was a kid. I was just terrified of it. As I get older, time is the bigger currency.''

Bradley said turning 40 triggered a change of heart, and he came to the conclusion that it's ''time to do it''.

Gaga, 32, relished the experience of working with the Hollywood star, admitting that their friendship made the experience much easier.

She told Variety: ''I think Bradley is an incredible filmmaker.

''I have acted before, but I've never been the lead actress of a feature film. Every day on set was such a thrill to watch him work. You can see the gears turning while he's working even when he's in character.''

Gaga also revealed how Bradley guided her performance in the new movie.

She said: ''I had the lines memorised.

''He told me the most important thing was to know what I was trying to say. To tell the story I was trying to tell in the scene. I could just throw it all away and exist in this precise but completely liberating environment. It was not rigid. It was an artistically free experience.''