Look.
Tobacco, marijuana, alcohol, even Heroin and Opium are 'ancient' pain relief remedies.
If it was the Civil war and I had to 'saw' your leg off - I wouldn't hesitate in using any one of these to lessen the impact.
Now when you have a 'hole' to fill, these work.
But when there is no 'hole', they don't work and actually make a 'lump' so to speak that you will 'trip' over!
The 'problem' is that people take these when there is no 'problem' in the first place to justify their use.
So they are 'tripping' all over the place.
Pain Relievers need 'pain' to work.
No pain and you get a nasty side effect instead.
People who take these consistently (without pain) and for 'recreational'

use find that when they do have pain or need their leg sawn off, that they have a very weak pain threshold and no amount of pain relief will alleviate their discomfort.
Find a person who has never smoked Pot and another person who has smoked it weekly for years. Saw their legs off and the 'non-smoker' when using it for the first time, would feel mild discomfort, while the pot head would probably die from the pain itself, even if he had 5 times more pot than the non-smoker at the time of the amputation.
Now, if I was Nursing and that 'smoker' gave me a look of 'anger' in his eyes - I wouldn't turn my back on him until I was absolutely sure the 'brat' was beyond a comeback, but as usual - their 'need for revenge' is obvious and he would attack me asap. I would of course kick his butt and in a Court of Law ...if you get beaten up by a Nurse, then you most likely 'deserved it'!