Dipper cannot remember the last time he lay awake at night, staring at the ceiling, impatient to fall asleep.
It started after Mabel's Sock Rock Opera. He had started falling asleep as soon as his head touch the pillow. He thought that was a blessing, until the air in his dreams turned acrid and tasted like burning plastic. Until a large singular eye lit up the darkness, illuminating over Dipper like a spotlight.
No matter how many times it happened, no matter how much Dipper braced himself the demon was a step ahead of him, and always always sneaking up behind him. Dipper hated that.
At a certain point, Dipper accepted that Bill was always watching, and even if his head was full of nightmares at least he was finally sleeping.
It only became a problem when he nodded off while sweeping the gift shop of the Mystery Shack. It got worse when he passed out in increasing increments.
Dipper cannot remember the last time he was awake, he's not sure what is real anymore but Bill tells him reality is an illusion. That he's finally where he belongs.