Emma Stone doesn't know how long her career will last.

The 'Birdman' actress - who is currently starring in 'Cabaret' on Broadway - feels ''very lucky'' for the ''incredible'' opportunities she has been given but sometimes feels ''overwhelmed'' because she is trying to challenge herself as much as possible.

She said: ''It's been wonderful but it's also challenging and I'm going into places that I've never really allowed myself to go before with 'Birdman' and 'Cabaret'.

''I feel very lucky that I'm getting the opportunity to do it and I don't know how long that opportunity will last - I'm trying to learn as much as I possibly can in this time.

''It's been incredible but also slightly overwhelming at times just because it's so different to anything I've done before.''

The 'Easy A' star also feels ''very lucky'' because she knew she wanted to be an actress when she was just 11 years old.

She told Psychologies magazine: ''I'm from Phoenix, Arizona and it was a nice place to grow up. There was a great youth theatre where I got to do improvisation at a very young age. I was 11 when I started doing improv - and learning where your passion lies at just that age, well, I was just very lucky.

''I think I knew I wanted to act when I was seven and in my first school play.''