Jesus, I loved this film. The Titanic lady was Kate Winslet. It was one of the few Carey films next to the Truman Show that I actually respected him for. The whole premise of erasing your memory was very appealing at the time as I was having some issues and was an emo f**k. But in retrospect it was a brilliant piece of work. I even dug this up a couple years ago and watched to get some fresh perspective on my skewed memory. I especially remember the twist with Kirsten Dunst's character and the Doctor being poignant as hell. Not to mention the brilliant scenes of Carey running away from the erasers through his memory.
As for the ending, shame on you man, go rent it. Its worth it to finish. Hell, you should watch it a couple times, purely to gain even more understanding and insight into the motives and flaws of the characters. If memory serves correctly the soundtrack wasn't too shabby either.