The 24-year-old star - who has been dating the British actor Dominic Cooper since they met on the set of `Mamma Mia!` in 2008 - admitted she would normally put her career in Hollywood before any man in her life.
Speaking of her role in the movie `Letters to Juliet` she said: "My character was very motivated by her job and not by her love life, which is kind of normal for a girl her age. I know it is for me. Sometimes I focus less on my relationship and more on my career."
The actress also claimed that being in a relationship can become "very warped" when you`re so in love with somebody.
She told Parade.com: "I think it`s common to meet somebody and fall in love right away, but the rest isn`t easy. When you`re in love, sometimes you just can`t see it realistically. The world inside a relationship can be very warped because of feelings and memories, and it all becomes jumbled."
Amanda admitted her own trans-Atlantic relationship with Dominic, 31, had been quite a challenge at times.
She said: "It`s never easy to be separated from someone you love. When your love lives in another country, it`s a lot of miles on airplanes, a lot of distance in space and in time. I always find it hard, even after you`re separated even for just a few days."