"He sees you when you're sleeping.
He knows when you're awake.
He knows when you get home from school,
And he knows what bus you take."
That's not exactly how the song goes, but I think the lines I added are implied. If he sees me when I'm sleeping AND when I'm awake... what else is there? He sees everything I do! It's a Christmas stalking. Normally I avoid puns, but in this case I'm not ashamed. It had to be said.