For a year or so I smoked casually when i was a teen in the 90s (to look cool) with intermittent bouts of heavy smoking over days at friends homes/etc. Probably average ~1-2 packs a week. One day i just got bored and stopped. Never felt any withdrawal signs.

I'm not countering your point of it being addictive. I was so, so so lucky not to have been hooked by that at all. I don't know if i just didn't smoke enough, or what... but it's one of the few points in my life i feel like i made the right choice. Weirder yet, it wasn't even a choice.. i just sort of stopped.