Interesting. Fio came across an old blog that Husband wrote while Fio was recovering from heart surgery several years ago and learned that she'd had such a bad reaction to massive doses of Vicodin (=hydrocodone) that she'd refused to take it so the doctor moved her to massive doses of Tylenol.
What was that reaction, you ask. The same as after her hip replacement--hallucinations whether she was asleep or awake. Yes, your Fio is not destined for life as a drug addict. She likes the world to make sense, to have cause and effect, perhaps the most outrageous hallucination of all.