Rebecca. The entire book is named after her, so you'd think we'd at least meet this woman in the novel. Instead, we hear her story from others: people who are fascinated and kind of obsessed with her. Because none of these sources are particularly reliable (they're all emotionally involved, after all), Rebecca remains a mystery to readers.
So what's in a name? A lot, apparently. There is something about the name Rebecca that seems to hold a certain power over everyone who encounters it. There are a thousand reminders of Rebecca at Manderley, from the flowers she cultivated, to her bedroom with all her things still in it, to her "curious slanting" handwriting (4.91). But none of these are as powerful as her name, which will always haunt Maxim and his second wife.
Speaking of Maxim's new wife, she doesn't have a name. Think about that for a second. Rebecca's name is the title of the novel, and our narrator – our protagonist – just goes by Mrs. de Winter, wife of Maxim. Why isn't the novel called Mrs. de Winter? How would the story be changed if it were?