She said: "I'd love to be a diva. But then I'd have to send so many apology notes for my abhorrent behaviour. I'm polite. I believe in manners. I say please and thank you."
The 'Man of Steel' star admits she was cripplingly shy as a young girl growing up in rural Castle Rock, Colorado, and wasn't popular in high school.
She said: "I hated high school. It was classic teenager stuff - I was a loner. I would bring a book and read at lunch. I was really moody."
However, the 38-year-old actress knew she would have to overcome her insecurities to realise her dream of performing on stage, adding to the UK's ELLE magazine: "Being an actress hasn't made me insecure. I was insecure long before I was an actress.
"It was just a question of overcoming my insecurity to be able to do it in front of people."
Amy has noticed that her two-year-old daughter Aviana - whom she shares with fiance Darren Le Gallo - has also inherited her mother's shy demeanour.
She added: "It's funny. She's a bit like, 'Why is everybody smiling at me?' and I'm like, 'You make them happy', and she's like, 'Can you tell them to stop?' "