Ah. That explains a few things.

Also, when you ask what painkiller the hospital is handing you, "Tylenol" may mean "Tylenol WITH CODEINE." If you are most people, you lose nothing in the distinction. If you are the 0.2% of people who have the paranoia reaction to codeine, it might put your sleepless night and next day spent crying uncontrollably - until it finally fully wears off - into a little more context.

I have explained this as well. Hopefully it will stick.