For the latter one that wouldn’t be shocking. Opium poppies because widespread crops in the Bronze Age. I’ve even heard a classicist say that it’s theoretically possible that some Bronze Age healer in Egypt could’ve developed a secret formula for painkillers that was just morphine as the non poppy ingredients were able to be harvested using the trade routes and technology of the era.

I think what might be more surprising is that we can consistently knock patients out for surgery without much risk of death and that we can stop people from dying after they’ve overdosed on opiates (though idk how hard it is to od on smoked opium).

And in the medical field try explaining to a plague doctor that the bubonic plague is a mild inconvenience to all but the poorest people today and can be cured with inexpensive pills.