I smoke, and certainly wouldn’t have started at 20. To me banning cigarettes is like banning turpentine in kids’ soft drinks. I have no problem with the alcohol & gambling age at 21; smoking can be the same. Pot should be treated in the same manner as cocaine, heroin, etc..
Then the question is; should there be a law for those who risk their lives and join combat units in the military , because under this law they can risk their lives, lose their lives, but can’t smoke or drink, or should an exception be made like concealed carry in my state.