The Superman Returns star, now 33, was floored by a series of "horrifying" comments she read about herself in a chat forum when she was 21, and decided then and there that Twitter and Instagram were not for her.

"I felt like I was standing in a roomful of people that were talking mean-spiritedly about me," she tells Fashion magazine. "It was then that I made a conscious decision to stay away from that negativity."

Now happily married to filmmaker Michael Polish, Kate admits she no longer cares what people online think about her, insisting that's not one of the tings she'll be thinking about on her death bed.

"At the end of my life, the thing I'm going to ask myself is, 'Did I love really well? Was I loved well?'" she explains. "Those are the things that are most important to me. If I feel like I'm successful in those two things, then I think I've lived a pretty happy life."

And the actress is no longer concerned about being on the best-dressed countdowns or on designers' wish lists because she has learned to accept her slim body type isn't for all fashion watchers.

"I'll look at someone like Beyonce and say, 'That dress is so amazing on her', but I know that my body type is completely different," she tells the magazine. "I have more of a boyish figure, so anything that's too loose or shapeless isn't the most flattering for me."