Actress Kristen Stewart uses a check sheet to mark her acting ability in her films.

The "Twilight" star always makes sure she looks back at her performances to see what she can improve on, but when she watched "Still Alice" she was blown away.

She was so impressed by Julianne Moore's portrayal of Alice, a professor suffering from early onset of Alzheimer's, that she barely noticed her own character, reports femalefirst.co.uk.

"I'm super technical, I will sit and watch one of my films with a little list of checks and balances and this finally took that away. Usually the first time is never a proper experience, it's always getting over hangups and weird memories, and this time it was just absolutely undeniable.

"What she (Moore) does needed to be done. It's so important," she told Salon magazine.

"I've seen it twice now. The first time I saw it, I was so blown away. I was present for a lot of what she did that was impressive in the movie, but for the things that I was not there for she so destroyed me (sic). I thought nobody else in the movie existed," she added.

The 24-year-old star plays Alice's daughter Lydia in the film.