The 39-year-old actress - who married playwright Andrew Upton 11 years ago -would love to relive the special day because she has no photographs to remember it by.
She said: "The only moment of my life I would possibly recapture is getting remarried again because we didn't take any photographs. We didn't have any money at the time and we couldn't afford a photographer."
Cate - who has three sons with Andrew - also revealed starring in new movie The Curious Case of Benjamin Button, about a man born elderly who ages backwards, helped her remember the most important things in her life.
She added: "In rehearsal we were talking about our relationship with our parents, about the first time you kissed somebody, it makes you remember the turning points in your life.
"The thing I physically learned for the film was a lot of dance moves. I thought a lot about my grandmother because a large portion of the film I am playing an 86-year-old who is dying in bed."