As OSS said, reactions are different for everyone. I had TJ surgery a long long time ago (not in a galaxy far far away) and had vicodin prescribed for me. Once I decided I wasn't in pain enough to need the meds and tried to stop taking them, that was a monkey that was harder to kick than I expected. After a while, your body just expects it. I take anti-seizure meds now, and at one point my doctor tried to lower my dosage because it was messing with my ability to do my job properly, and after 3 days of a lower dosage, I was getting the shakes, I was sweating, my heart was pounding, and all this was from a non-narcotic, non opioid med. Someone else might not have this problem at all. Someone else might have it worse. I think this is all stuff that people academically are aware of, but I just think it bears repeating. Addiction is weird, and sometimes it creeps up on you. Yes, taking drugs is a personal choice, even necessary, prescribed drugs are a choice, but addiction is insidious. It happens before you're aware of it. It's like weight gain. You can suddenly step on a scale and be like "whoa, when did this happen?" And people say "well just don't eat, how did you not know you were gaining weight?" Instead of demonizing people and saying "just don't do drugs" I think it helps to understand the mechanics of how addiction happens.