Creepy or not creepy?

Last night, I asked Sam if he wanted to watch a movie.

Sam: "that's a good idea."

me: "okay" [think to myself, maybe the Polar Express?]

Sam: "how about the Polar Express?"

me: "wow, I was just thinking that."

Sam: "I know."

me: "you know? how do you know?"

Sam: "I heard your voice in my head."

me: "you heard my voice in your head?!"

Sam: "yeah." [shrug.] "I hear your voice in my head all the time."