Dickens, not Charles

Ed has sleep apnea and recently got a new mouthpiece that juts his lower jaw out so he can breathe better while sleeping.

“How do you like your new mouthpiece?” I inquire after the first night.

“Like the dickens,” he answers.

“You love it like the dickens?”

“NO!”

“You hate it like the dickens?”

“YES! I hate it like the dickens.”

Still, the nights are strangely silent.

"Like the Dickens" has nothing to do with Charles Dickens. Dickens is a euphemism, specifically a minced-oath, for the word devil, possibly via devilkins. Shakespeare used it in 'the Merry Wives of Windsor, 1600: “I cannot tell what the dickens his name is my husband had him of.”