Since there were so many fakeouts at the beginning...

with the psychiatric admission being a ruse, the home invasion being a seduction, the doll on the road being a dream, I started to wonder if anything was really happening.

As somebody else has commented on another thread, I wouldn't have been entirely surprised if the movie had ended up being one big fakeout where it would have been revealed Patti was a fellow inmate at the asylum at the beginning and just absorbed the story.

I think I would have liked that ending better as the original was extremely abrupt.