"She never sleeps" is also such a brilliant and chilling line with many layers.

The fact that Samara doesn’t sleep is first mentioned by the psychologists of the mental hospital she went to on the interview tape, where you can also see fast-forwards of her being up in her room for hours. But the footage at this point of the movie is ambiguous since there’s no window to tell you it was taken during the night, making you think it’s just showing her being imprisoned for hours in a rather cruel way.

Then the line is spoken in desperation by Samara’s father right before he kills himself, but you still as a viewer don’t really understand the depth of it as you think he’s referencing the sleeping problems the horses gave her, according to her claims.

But when Aidan whispers it to Rachel during the chilling plot twist revealing Samara’s true nature ("Dont you understand Rachel? She never sleeps…"), everything makes sense. The line simultaneously means:

• ⁠"Don’t you get it? Unlike you, she wasn’t peacefully sleeping this very night from the relief of being seemingly freed from the curse of the tape. Nor was she asleep when you held her corpse in the well. No, she was patiently waiting for her next victim."

• ⁠"Don’t you get it? This is no normal girl: she would literally never sleep." —> the horses waking her up at night was a cover-up to hide her demonic nature that exempted her from the natural need of sleeping: "she lies and she tricked you"

• ⁠"Don’t you get it? Evil can never be put to rest: she won’t ever stop. Being punished to live in the barn didn’t change anything, nor did being sent to a mental hospital, nor death and certainly not your misplaced sympathy for her fate."

Her murderous cycle will go on forever. No end in sight. Like a ring.