The ultimate thing that convinced me not to smoke was watching my uncle die of lung cancer, and being unable to quit the thing that was killing him.
I'm somewhat relieved that tobacco references are considered "adult" now in entertainment. The amount of smoking I saw in movies and TV (and around my uncle) normalized it for me, even though I knew how unhealthy it was.
For my high school cohort the video interview of the person still smoking after having had a laryngectomy really drove home the powerlessness of addiction.
The problem is seeing all that... And then seeing family members and friends smoke on the weekend... It puts it in this weird "safe to try, but not safe to keep doing" slot.
Nicotine addiction is very subtle, for many it's hard to recognize until you're hooked.
I'm somewhat relieved that tobacco references are considered "adult" now in entertainment. The amount of smoking I saw in movies and TV (and around my uncle) normalized it for me, even though I knew how unhealthy it was.