"Boo!" "EEK!" Freaked out?

[Elennar Starfire]

What freaked me out was that before I watched FotR, I knew exactly how Celeborn would say "Eight there are here yet nine there were set out from Rivendell," and before I watched TTT I knew how Gollum would say "cold be heart and hand and bone, and cold be travelers far from home," and I never saw the previews. I thought for a while that it was because of the books, but those lines aren't in the books like that.