I had one....
I was in the hospital and within a few days after getting my guts cut open.
God knows what drugs they were pumping into me.
It was no fun but not as bad as loosing my mind after a previous surgery about 25 years before. Back then, Morphine.....a blast in the ass every 4 hours ....I went nutso. It's tough to find your mind when it's missing.
I don't do well with hi-tech pain killers either. (Oxycodone?)